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BIOL 3324 Human Physiology - BIOL3324_Lecture06
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00:01 All right, now, I think can get started. Only have a
00:04 windows opened. I can't even find I'm looking for. Here we
00:10 And here we are the day before exam. Some of your panicking.
00:16 , not really, but at least me and going What's on the
00:19 Everything's on the exam. Everything we about, everything we're gonna talk about
00:23 be on example up through today's Andi, I don't think we'll take
00:27 time hoping we don't take the entire . I can't promise that because you've
00:31 how slow I talk. Even though talked like a auctioneer. And what
00:35 gonna do today is we're gonna look we're gonna take that information that we've
00:38 looking at this idea of great potentials action potentials and sales talking to each
00:42 . We're gonna kind of try to it all together to understand what's going
00:45 inside the nervous system before we actually into the nervous system. And in
00:49 , if you think about what are things that we've been covering? This
00:51 have you guys even thought about Like what if I've been learning you
00:54 always do that whenever you're in a is kind of just kind of take
00:57 step back and say, what was point? And if the answer
01:00 I don't know, Then one of things happened. Either Professor really
01:06 which is a possibility. I'm not pretend like that's not a possibility.
01:10 you weren't pick getting the big And so if you kind of look
01:14 the big Unit, what have we learning? We've been learning baseline how
01:18 body works, how cells talk to other, right? How they communicate
01:22 general, what the general structure is what the overall layout is. And
01:27 is gonna propel us into all the field. So it doesn't matter which
01:30 you're actually looking in or where you're you are in the body, you
01:33 . Oh, yeah. Cells talk each other. So if I know
01:37 sells, talk to each other and is how it works in one
01:39 this is must be the way it in another system, which is so
01:41 easier, une easier way toe learn rather than trying to memorize each and
01:46 system individually. It's dealing with broader concepts and bringing it together.
01:52 so that's kind of where we are here is we're taking these little tiny
01:56 were kind of bringing them all And what we're looking at is something
01:59 not going to see a lot of we look a cardiac muscle. This
02:02 an electrical synapse, and I bring up now just so we could get
02:05 out of the way that we could forward. The electrical synapse simply is
02:08 two cells talk to each other and connected by connections, right? And
02:12 the idea is that you're moving ions between cells. Most cells don't do
02:18 . Remember how the most cells Are they connected to each other?
02:22 . So how did they talk to other? Chemicals. They throw chemicals
02:26 each other. Right? And so . What we have is you can
02:28 the gap junctions and saying, I'm passing arms back and forth and
02:32 two different ways that we can do . We have what is called reciprocal
02:35 what is called rectifying. Reciprocal is of what they're trying to show you
02:39 If you look closely, you can a little tiny arrows, Um,
02:44 in here and saying, Look, going this way and I'm going that
02:48 , right? And so what we here is we have current moving in
02:52 different directions and so they're talking to another like so and so it's kind
02:57 this rolling. Uh, this rolling basically is equally efficient in both
03:03 Said be reciprocal. Rectifying, on other hand, is one, uh
03:08 one direction, and that's what's really of being shown up here. Even
03:12 this is the same picture, they of threw it in here. It's
03:15 , Look, the current Onley allows to go in one direction. And
03:19 course, if I keep allowing that happen, eventually I'll reach equilibrium.
03:22 what I have to do, I to let the ions out of the
03:25 and the islands come back into the cell, and it just keeps flowing
03:29 that direction, right? It would like walking out of this door to
03:33 right, running around the hallway, back in and saying, Okay,
03:36 just gonna run back through the door right. And so you basically
03:40 have a current flowing in a particular . So electrical synapses can use one
03:45 these two methods. Um, in you're going to see in the future
03:49 not really going to dive deep into . I'm just trying to show you
03:52 , you know, it's there's there's and layers of complication underneath all this
03:57 because what we're interested in in the that our body mostly signals is through
04:02 synapses. All right, through these signals now a synapse is simply the
04:11 between a neuron and its target. right, that's the easiest way to
04:16 it. It's basically we take that on terminal. We bring it
04:20 very close to the cell in which going to be talking. So this
04:24 a form of peregrine interaction, Because that's what peregrine meant and what
04:31 like. It's like you and your in a car. Remember? We've
04:37 talked about this. I think I it once before. Did you?
04:39 have siblings? You guys in here siblings here? Did you ever play
04:43 I'm not touching you game? You what that is? that's when you
04:46 right up. Next time you put hand right in their face, you
04:49 be mad at me. I'm not you and they kind of sit there
04:52 go right. You can't. That's going on. Here is these two
04:56 are almost touching, but not And so what we have is we
05:02 a cell that is the sending selling . We have a cell that's a
05:05 sell. The sending sells the pre sell. The receiving sells the post
05:09 sell. The connection between them is to as the synapse, the space
05:14 between them. Right here. Everything there is called the synaptic cleft.
05:22 so what we have is we have close interaction and so in action potential
05:28 what is going to be sending a along the length of the acts on
05:32 to this point right here. And can see the little lightning bolt flashes
05:36 on the ax on those they're supposed represent action potentials traveling. And we
05:44 , if you listen to the video I posted last night, so sorry
05:46 make you have to listen an extra minutes of me, right? But
05:50 learned that an action potential is simply opening and closing of voltage. Gated
05:54 . Which type of voltage? Gated You guys remember? No, it
06:02 like I didn't watch that Sodium. it's a vulture. Gated sodium
06:07 That's the opening. And then the of the vulture gated potassium channel in
06:11 voltage gated sodium closes so that you see this peak and this fall,
06:17 this is gonna be along the entire of the ax on and then So
06:21 is how the ax potential propagates itself how it rolls. It basically moves
06:26 the way down the length and it down here. And when you finally
06:29 down here to the acts on you no longer have these voltage
06:33 sodium and potassium channels. You change type of channels you have. So
06:37 you have different channels, what do expect? Different responses, right?
06:44 so that's what happens. Instead, have a voltage gated calcium channels,
06:47 you're no longer propagating a signal. you're responding to the signal. And
06:52 what happens is is calcium comes rushing , and when calcium comes rushing
06:58 It causes so calcium comes in. causes vesicles containing neurotransmitter to move to
07:07 into the terminal to the pre synaptic and open up and release its contents
07:13 the synaptic cleft. And now you a chemical signal. Chemical signal moves
07:19 the synaptic cleft binds to a receptor causes a channel to open on the
07:25 synaptic cell. And on the post sell, you're getting a response.
07:30 response would be a grated potential. right, so what we have here
07:35 we've got action potential results in the of neuro transmitter through a couple of
07:40 tiny steps that will go over again again and again until you're sticking of
07:44 it right, which causes the opening a channel in the post synaptic
07:49 which produces a greater potential and with potentials. I can do things with
07:54 one of things I could do with potentials, I can produce an action
07:58 . If the greater potential is strong . I can signal or cause If
08:03 next in line is is another I can create another action potential,
08:07 I could literally have a cell tell cell to fire, which tells another
08:10 of fire, which tells another cellar , which tells another cell to
08:13 And when I say that it sounds stupid, well, why should be
08:17 far? Well, because they're processing . Alright, each of these
08:21 when they're when they're responding, that part of the process. Just like
08:26 computer chip. I'm gonna pretend like don't know how computer chips work.
08:30 here know how computer chip works? , no resistors and circuits.
08:34 So let's all just pretend like we . And that's kind of what's going
08:38 the side of cell. It's the circuitry of the brain. Each cell
08:44 responding to that signal to create a . All right, now, this
08:50 path pattern you can see it's what refer to as being unit directional once
08:55 raised all the ink, so notice moving down the pre synaptic side,
09:01 I'm causing a response in the post cell. The post synaptic cell isn't
09:08 right back there, not having a . It's one cell telling the next
09:13 to do. That's what's occurring at synapse. Now we're going to see
09:18 we can have a conversation in both . But the neuro transmitter and that
09:24 from the actual potential to the neurotransmitter producing that greater potential is uni
09:29 It's always pre synaptic to post Yes. No, the calcium is
09:36 , the calcium is flowing into the synaptic cell. We're gonna We're gonna
09:42 this out a little bit because this just the big picture right here.
09:45 right? Yes, ma'am, of . That's absolutely right. Think about
09:54 like a dance. Alright. In dance, you have someone who's
09:58 Typically, it's the male but kind woman lead in a couple dance in
10:04 male female. That's of course, . It just depends on how the
10:08 arranged. So pre synaptic just simply to sell. That's sending pro synaptic
10:13 means the cell that's receiving that's the definition. Yeah, does not.
10:23 now, we're not gonna be dealing that. That's specific to,
10:27 to the electrical the wrecked because there rectify IRS on rectifying synapses, but
10:32 not going to deal with those that's the beyond this class. All
10:39 now how the vesicles get there have already talked about this? Remember?
10:44 said they were transported. Right? this is just trying to show
10:47 Look, I made my vesicles. my neurotransmitter. I used Antero grade
10:52 to move it down there, and put my vehicle full of neuro
10:55 and I sat it there and stored my neurotransmitter waiting for that signal.
11:00 this is what's kind of cool. think again, there's a lot of
11:05 you do not need to know on slide. All right, this is
11:07 highly detailed slide, but what I to show you is is that that
11:10 ical isn't just floating out there in side is all kind of going la
11:14 la, la, la It's actually right up to the to the plasma
11:20 , and it's almost joined with, not completely opened up to. All
11:26 , So this is what I'm showing it. It prevents complete fusion,
11:31 it's set up ready to fuse with plasma membrane to release its content.
11:37 it needs is a signal, and can see down here if you look
11:41 the bottom of the graph, what it it's the presence of the
11:44 All right, so that's what I'm you right there. That calcium,
11:49 it comes flowing in, causes this called complex, um to be removed
11:55 complexion is removed. Then the next is fusion and the neurotransmitters being
12:02 So what we have here is we a situation where all the vesicles are
12:05 in place. The neurotransmitter already has made. It's all stored up,
12:09 to go. All you need is action potential to come down to the
12:13 on terminal to allow the calcium into cell. That's that bottom step.
12:20 the calcium flows in that vesicles fuses releases its neurotransmitter. So you can
12:27 this is an incredibly quick response. talking milliseconds. Remember when you looked
12:33 the graph of the action potential? you remember? Did you guys look
12:36 see what the time frame on that . It's like whenever you look at
12:39 , look, go back and It's like 0.4 milliseconds, right?
12:44 incredible. That's just for that. of the things you can imagine.
12:48 had little time. It's fast now , you don't need to know all
12:54 these different things back in the I used to teach the details and
12:58 would cry a lot. So, know, I felt bad.
13:03 What I want you to see here kind of what this looks like.
13:07 , this is the neural muscular All right. Neuromuscular Junction tells you
13:12 neuron to a muscle, but this be for neuron to neuron. All
13:17 , But look at how the uh, demonstrates this. You can
13:21 here. Here is the synaptic Alright. In muscles, it's called
13:25 Motor in Plate. I don't know it's labeled that way here someplace.
13:29 , but you can see. Look the look at the pre synaptic.
13:32 look at all of those vesicles lined and ready to go. Right.
13:39 vesicles are ready to release. So someone throws a baseball at your
13:44 what are you ready to do? right. You don't have to sit
13:49 and let me make some neuro I hope I could make it fast
13:53 and get it down to the terminal enough so that I could move my
13:57 . It's ready to go all it is a signal, and that's what
14:00 is allowing it to do. So can imagine all the neurons in your
14:05 have the neurotransmitter already in place in vesicles lined up right up next to
14:11 plasma membrane, ready to go. it needs is that action potential to
14:15 that influx of calcium when the calcium in that allows the vesicles to open
14:21 and release their neurotransmitter. Now, told you guys something a couple days
14:29 , so I know this has got go back in time. We're talking
14:32 signaling pathways, anything that I turn , what must happen? I got
14:38 turn it off right. Otherwise, dad yells at you for keeping the
14:42 on all night. Remember, that thing is true here. If I'm
14:48 neuro transmitter, remember, neuro transmitter simply a signal between two cells.
14:53 telling that sell? I want you respond like this. Do you want
14:57 keep telling it to respond, even so you need to kill that
15:02 So there must be a termination signal every signal that we create. And
15:07 for the neuro transmitter that's being released need to get it out of that
15:11 cleft as fast as possible so we clear it for the next signal to
15:15 along, depending upon how long that's be. It could be in another
15:19 . It could be in seven All right. It doesn't matter.
15:22 idea is that I need to make that the slate is clean so that
15:27 signal could be made. And so gonna have a form of termination.
15:32 , Now, termination is simply that of getting rid of the neuro transmitter
15:37 of that synaptic cleft. And there's lot of different ways to do
15:41 And again, in the picture, have a whole bunch of different types
15:45 neurons. You do not need to which one does which, but you
15:49 know the different mechanisms that are All right, so there are basically
15:55 ways that we can terminate a All right, up over here,
15:59 have a seat of cooling. So is a calling. Uh uh.
16:05 we refer to as a colon uh, neuron. And so it
16:09 acetylcholine, and we have an enzyme sits in there and it's like looking
16:15 acetylcholine and ready to chew it up destroyed as fast as it's being
16:19 Its like the world's most dangerous game Red Rover. Remember Red Rover?
16:24 Rover? Red Rover? Let whoever over the first one run across and
16:29 toe. That's what it is and instead of you just kind of trying
16:32 run across, you've got, I know, wolves trying to eat you
16:35 you're trying toe run across. Maybe you guys played Frogger. That's probably
16:41 before your time, right? It's the fourth game that was ever
16:45 right? But the idea is, trying to get to a destination,
16:49 something is trying to kill me along way. That's what the enzyme
16:53 It's there to destroy the neurotransmitter before has a chance to stick around for
16:58 given period of time. So you imagine for every I'm gonna make up
17:03 . So for every 100 molecules that being released, you can imagine that
17:06 chewing up half of them before they get across. So what you're trying
17:10 do is you're just trying to eliminate fast as possible. And then that
17:13 is also capable of binding up to neurotransmitter and chewing it up at the
17:20 of the receptor. So if it's up to the receptor, the enzyme
17:22 along and showed up there so that no longer bound to the receptor.
17:26 you're no longer producing signal. The thing that I can you can defuse
17:30 . None of these things are showing , but you can imagine this is
17:33 is doing my neuro transmitter here. just gonna use the middle one.
17:36 my neurotransmitter goes la la la la it goes alright. If it's not
17:40 the synapse, can't buy into Interceptor you can't buy into Interceptor No
17:45 Well, sort of. I you can imagine there's receptors all throughout
17:49 body that are capable of binding So there are enzymes that just in
17:53 , looking for things that shouldn't be . They're chewing things up, and
17:57 molecules have a half life, so gonna probably fall apart anyway. But
18:01 the general sense is that if you defuse away from the synapse, you're
18:04 gonna signal. And so that's one the things that can happen is that
18:07 or the neurotransmitter could diffuse out. thing you could do is you're gonna
18:12 a neuron uptake, its own neuro . And what it's gonna do is
18:18 thing you would do if you were around your house. You have found
18:21 all this extra paper lying around, you gonna do with it? Collect
18:25 . But in the trash or I could recycle this and use it
18:29 scratch paper, and that's what neurons . So let's see, in terms
18:33 examples, you could look at Uh, basically, all the ones
18:37 the bottom are showing that as well , well, all of them on
18:40 top as well. So all of are showing it. You can see
18:45 just showing you there's myself. Doesn't matter which one you look
18:51 All right. So I'm just gonna sink on this slide. You can
18:53 see it. All right. So idea here is I'm basically taking up
18:57 stuff that is still there. I'm it up, and I'm either gonna
19:01 it. So that's what you're seeing in the colon ergic receptor. Basically
19:05 it down and then rebuilds it. the others are probably repackaging. Each
19:10 ones are unique, and then the thing I could do, and this
19:14 kind of a unique thing. We think that this was possible, but
19:17 can have other cells take up the . In other words, it binds
19:21 a receptor, but it's not actually the receptor. Instead, what's happening
19:25 that the cell that's receiving it will it in to remove it from the
19:30 . And then we'll break it down that it's no longer available. And
19:35 what this is showing you up here this corner. All right, so
19:41 were representing Astra sites, and you see that they have binding sites for
19:46 neurotransmitter. They're taking it up in it from the synapse. And
19:51 in this way, what we're doing we're just clearing out the synaptic cleft
19:55 that we can have very distinct periods time where signal is occurring and when
20:01 is not occurring. Does that kind makes sense? Got one head nodding
20:07 . Do we have thumbs ups? have No one asked questions. That's
20:11 a good thing. All right. , ultimately, this is what an
20:17 potential is doing. Actual potential is from one side of the sell down
20:21 the acts on terminal cause release of . Neuro transmitter is released out in
20:26 synaptic lapse. Binds to a receptor a response in the post synaptic
20:34 All right, these responses in the synaptic cells are gonna be grated
20:40 All right, But we have special for him because we like to confuse
20:44 , right? That's why we name in very, very tough and difficult
20:47 . We're trying to figure out how we torture students in the classroom?
20:53 not buying it. Okay? What do is we name things like I've
20:58 before. We name things for what do, and so we can either
21:04 a cell, right? Neural transmitter tell the cell become excited. Or
21:10 we can do is we can tell cell you're not allowed to get
21:14 so stop it. Stop what you're . Stop. Right. So that
21:19 be inhibition. So we can cause or weaken cause inhibition. And so
21:24 you can see there's our synapse And when in that video, if you
21:28 the video, I pointed out with potential had these little tiny graphs right
21:32 and in a greater potential. What have is you have a small changing
21:38 membrane potential in response to the signal . So magnitude in a greater potentials
21:45 dependent upon the magnitude of the All right, So if the neuro
21:53 binds to a receptor and that opens channel and that channel happens to be
21:58 cat ion channel, typically what's gonna is that sodium is gonna be moving
22:02 the cell. And when sodium moves the cell 99.9% of the time,
22:09 causing the cell to be deep and that is what we refer to
22:13 excitation. All right, so that's this is trying to show you.
22:19 saying, look again, you have just kind of understand this is a
22:23 system, you know, binary right? Basically on off.
22:30 So if this is the off moving up is the on stage.
22:37 there, that would be a All right, But what we're saying
22:41 look, I'm going to stimulate the so nothing's going on. I'm
22:45 And so I'm gonna give it a small stimulus. Alright, we're gonna
22:49 gonna use a terrible example, because is not producing a greater potential.
22:53 it's easy to visualize if I come to you and take a little tiny
22:57 and I push it against your you would feel it right, but
23:02 wouldn't hurt. It would just be , Okay, you're poking me.
23:04 it. All right, so that be a small response to a small
23:09 . Alright, now imagine I come you and poke you a little bit
23:13 . Would you respond differently? Would have a larger response? Yeah.
23:18 . Now imagine me taking a running at you and then double fisting that
23:22 and just jamming it into your Would you have even larger response?
23:28 . Okay. Now, presuming that response is the same, it's like
23:33 and then screaming Al right, That be the equivalent. And that's what
23:38 seeing here. This is the This is me coming in with the
23:45 at different strengths. Each of those represent different strengths and let me erase
23:49 ink. All right. So brown weaker than blue, which is weaker
23:54 green, which is weaker than And then the response is over
23:59 You can see I get a small potential. I get a small,
24:05 potential. I get a potential that threshold. And what happens when I
24:10 threshold? What do I get? Shin Potential A response, which is
24:16 you see that massive peak. All , so what we're producing here,
24:22 greatest potential because it is stimulatory is to it as an excited Torrey
24:29 Where is it happening? It's happening the post synaptic cell. So we
24:34 it's an exciting Torrey post synaptic And all of a sudden all those
24:38 letters go away from being scary. just descriptive and easy, right?
24:46 this is Anak Shin potential can cause of a neurotransmitter. If the neurotransmitters
24:52 , it results in an e p p, e p s ps or
24:56 potential. So that means by definition can vary magnitude. They have no
25:01 period because great potentials don't have refractory Onley action potentials due. And then
25:07 , whenever you have something that, a greater potential. You can add
25:11 up together, all right, And get to that in just a
25:15 Now, the converse is true as . I can release a neuro transmitter
25:19 is inhibitory, all right. And does the exact opposite. It basically
25:25 the outflow of potassium. And Because the outflow of potassium that's gonna
25:30 the inside of cell more negative. moves me further and further and further
25:34 from what is called threshold. So basically moving further and further away from
25:39 action potential. All right, so basically saying, no, you can't
25:44 stimulated. You have to move away stimulation. You're becoming less and less
25:49 I should say less unless you are likely to become stimulated as a result
25:54 inhibition. All right, and because this is the greatest potential has
25:58 same characteristics. It varies in It has no refractory period. And
26:02 can be some together to make larger larger and larger membrane potential changes that
26:08 moving further and further away from And that's what these two little graphs
26:12 on the bottom are trying to show . All right. So the difference
26:16 the E P s P excited Torrey synaptic potential and the I P s
26:20 inhibitory post synaptic potential is the direction which the membrane potential is going.
26:26 di polarizing with E P s I'm hyper polarizing with I ps
26:30 and it's just a result of the of neurotransmitter that is binding to a
26:34 . And what type of channel it to be is allowing sodium to go
26:38 or is allowing potassium to go out out for a second. Because there's
26:43 potential for this on the test. it just sodium and potassium? The
26:49 says No, what we have up chlorine as well. All right,
26:54 I can cause chlorine to flow into cell, which would make the inside
26:57 the cell more negative as well. right, so it's not just
27:00 Potassium chlorine can also play a role this as well. At least it's
27:04 is the most common type that doesn't any others, but I'm almost 100%
27:09 . I don't ask anything else. like, What about calcium? Don't
27:14 worry about that? Yes, Chlorine a bugger. All right, so
27:25 , we're talking about equilibrium. You ready to just kind of
27:29 Okay, I'm done with this. gonna go to law school,
27:33 All right. So the equilibrium potential chlorine is about minus 70. All
27:41 , So if I open up chlorine and on arresting neural, which is
27:45 minus 70 what's chlorine? Gonna dio gonna flow into flow out or
27:49 right? It's gonna do nothing at . So what's gonna happen is is
27:53 I'm stimulating the cell so that is polarizing, Then chlorine is gonna start
27:59 into the cell because you're no longer its equilibrium potential. Right? But
28:04 I start hyper polarizing selling, I chlorine channels open. What's gonna
28:07 Chlorine is gonna flow out of the because it's below minus 70. So
28:11 moved relative to where the resting potential . Which is why we tend not
28:17 talk about it. Because it's a of a It's kind of one of
28:19 pain in the butt ones where you to know, Where am I?
28:22 to three equilibrium potential, right. calcium or is not calcium,
28:27 um, potassium is easy because we it's equilibrium potentials. Minus 90.
28:32 you open a potassium channel, it's flow out of the cell. It's
28:35 going to do that right, because trying to trying to bring that
28:40 Tu minus 90. It's just too away. If I open up a
28:44 channel, sodium is gonna Russian because equilibrium potential for that is that plus
28:49 and you're so far away that sodium just gonna Russian themselves fast as I
28:54 . Alright, so chlorine is That's why we kind of tend to
28:57 it. But it's doing its thing upon where which direction We're actually
29:04 Yeah, off ESPN. I uh, after all right. So
29:13 is where I get really frustrated that teaching online versus teaching in the
29:17 because if I had 100 and 50 in here, I'm not mad at
29:20 guys. I'm just mad at the 550. You guys in here,
29:24 could do a visual representation of what looks like. And so I said
29:28 in the video. I want you imagine for a moment I want you
29:30 take a pebble, and I want to look at a nice, smooth
29:33 that has never been disturbed. I you take a pebble and I want
29:36 to drop it into that pond. are you going to get? Ripples
29:41 ripples are gonna move away from this where that stimulation occurred. That's what
29:45 greater potential looks like. It literally away from the side of excitation.
29:50 right, on the side of stimulation probably the proper term. But what
29:54 to the ripples over time? Do grow? Do they say the same
29:59 , or do they get smaller in pond? They get smaller,
30:04 I mean, think of the infinitely thing. Why? It's because there's
30:07 resistance is why that happens in a . But it's kind of the same
30:11 is that if you're thinking of, got ions moving into a cell.
30:15 the point of where stimulation current. got ions moving into the self.
30:18 moving into the cell because they're attracted a negatively charged ion, right?
30:25 so the moment that they kind of up to the other island go
30:27 how you doing? They're no longer the pool that you're measuring right.
30:32 been neutralized. And so as you further and further and further away from
30:36 side of stimulation, you have fewer fewer single ions. Which is why
30:42 like using the example of the two next to each other because we can
30:47 pairing up right? And so you imagine, Here I am. I'm
30:51 eye on the side of stimulation. so many of us were like,
30:55 , we're trying to find our and then you're kind of wandering further
30:59 further away and all your buddies, don't know what girls call their
31:05 You just call him buddies Gallop. see it just doesn't work. Guys
31:11 buddies, all our buddies air hooking . We're just kind of like I'm
31:16 only one over here. But if were to measure me, there'd be
31:19 here at the sight of stimulation. 100. And that's what that difference
31:25 charge is. Why you see that change? Did that answer the
31:31 Did I get a thumbs up? at all. You demonstrate because all
31:38 , we're gonna do a visual. ready? We're backing up all the
31:42 online. Don't get to see right. We're gonna do the
31:47 We're gonna start over here. We're finish over here. It's gonna suck
31:49 there's only 12 2468 10. There's of us. Ready? We're gonna
31:54 the wave. Ready? Go. , you guys. Yeah,
31:58 You're falling asleep in the background. gonna try it again? Because the
32:02 is a response to the person you , With only 10 people. I
32:07 see who's doing it. Try it more time. Ready? You're not
32:12 cool for school because then I get call you out. Ready? All
32:16 . That's an action potential, You saw there was a detrimental movement
32:21 the classroom. Now imagine 150 people here doing that. It's kind of
32:25 . And you can't say you've ever the wave in a classroom other than
32:28 this class. Now with the greatest . What it is is notice We
32:32 at one side of the seller, in the other, the greater potential
32:35 create a wave here, go, so it doesn't go very far.
32:41 right, so you guys don't know to do. You're like Okay,
32:44 , I'm used to do It's kind the same thing. It's just a
32:47 outward from the side of stimulation. that's how we do it visually.
32:52 it's always fun because you've got the who are like I'm too cool for
32:55 . You can't make me do the And we had harassed him for 30
33:00 . Mhm. But the action potential it starts, it keeps going all
33:07 , that's the kind of the key . They're all right. Once it
33:12 , it keeps going. So that's we do the visual representative, because
33:16 trying to make you visually see the in the pond. That's not always
33:21 to see. It's easy to see doing this right when you're in the
33:25 of it could also make you stop people in, like okay, do
33:29 way stop people like it's like, , then where are we on that
33:34 ? All right, so we got . Torrey, we have inhibitory,
33:40 these air single grated potentials and what trying to do is we're trying to
33:46 that signal that that post synaptic potential need it to get to the axon
33:53 . And if you're getting to the Hillock, what you're trying to do
33:56 you're trying to bring an action potential you're trying to produce that action
34:02 All right, so we're kind of a chicken and egg here,
34:05 We've just described what the action potential doing, and now we're gonna try
34:09 talk about how we produce one. on the dendrite on the receiving and
34:13 getting these greater potentials. And this kind of what a neuron looks
34:17 Does the neuron look like it's all its lonesome? The little blue things
34:21 other acts on terminals, yellow things accent. Excuse me? Are,
34:25 Astro sites? Do you think this cell right here is getting a lot
34:31 input from other cells? Yeah. is like you on your favorite form
34:35 social media. I'm just gonna pretend Facebook because I'm old and, I
34:38 know, tick tock and all the strange things there that are ruining your
34:42 . All right, let's pretend for moment that you are reliant on your
34:46 million friends that you have befriended on , right? All your closest
34:51 Yeah. And you are dating and you're trying to make a decision
34:55 whether or not you need to dump person. And so you go to
34:58 four million friends on Facebook and Hey, I'm gonna conduct a
35:02 Should I dump this person, or I stay together? And then now
35:07 just waiting for all that feedback from four million of your closest friends to
35:11 out what you need to do, ? Have you ever done this not
35:15 about breaking up with somebody? But you had a poll to find out
35:17 information? Yeah, and that's what can imagine is each one of these
35:22 is producing a signal, right? if you are that neuron, if
35:27 this purple neuron you can imagine you're input from some cells that are saying
35:32 want you to turn on. I you to become excited. Your
35:34 Other cells are saying No, no. You're not supposed to be
35:38 . And you're trying to figure out do I do all right? Because
35:42 cells are creating e P s Some cells are producing I ps ps
35:47 you and each of these things need well the island's air flowing in.
35:51 need to reach to a certain threshold order for you to produce your action
35:56 . And this is where summation All right, You heard the words
36:00 mate, these cells are capable of being some that's what greater potentials.
36:05 so what you're doing is you're adding the different magnitudes. You have things
36:09 are causing deep polarization. Alright, could be small, some could be
36:13 . You could have other cells that producing inhibitions. So basically hyper
36:17 some could be small, some could big and the net result of all
36:22 these different inputs. If they're enough get you over threshold, it's gonna
36:27 an action potential in the purple cell will then travel down the axon.
36:32 summation of the E P s ps the I PS PS equals a g
36:37 S p or the grand post synaptic , right? You gotta say it
36:43 the grand. You know, it's just grant grand post synaptic potential.
36:48 right, now the type of summation we could do is what is referred
36:52 as either temporal or spatial. without me flipping this wide slide,
36:56 know that you read this stuff, we're not even gonna do that because
36:59 know that skimmed everything. So what temporal refer to? We hear the
37:04 temporal time. Good, good. That's what I heard you say.
37:08 though you may not have said All right, it's hard to see
37:12 matching division, right? And then a spatial refer to space.
37:18 so, again, simple terms. see how it applies. All
37:22 we got temporal summation on spatial This little picture right here kind of
37:26 you that. All right, So we're gonna do is we're gonna walk
37:28 no summation of spatial tome or spatial temporal. All right, so we
37:32 get a vision of what's going on . We're going to demonstrate. This
37:35 well. So what we have here we have a single neuron,
37:40 This is our receiving. So this our post synaptic cell, and then
37:44 have a Siris of different pre synaptic and what we're going to say is
37:50 pretend one. I'm just gonna put one right there. Pre synaptic cell
37:56 . All right, so it's just by itself. So over here at
38:00 dendrite, if you measure that, see there's that nice little deep
38:04 but that deep polarization is going to down the cell and get to the
38:08 hillock. And it's not quite strong to get the threshold. If I
38:11 get the threshold, do I get action potential? Nope. No action
38:16 . Um, measuring way down here the acts on just to prove
38:19 All right, so this e p P does not have the big enough
38:24 strong enough magnitude to produce an action by itself. But let's bring in
38:30 buddy. Let's say number two fires with number one. Okay, so
38:36 what this is showing you. Look we get up here. We get
38:39 much larger grated potential, much eh? PSP, we've some the
38:46 MPs piece together. And so what we get? Well, if we
38:51 here at the Axon Hillock, we actual potential being produced. Now they're
38:57 you that two are occurring here, it's not always gonna be,
39:00 It could be one. It could seven. It just depends on how
39:03 you are, all right. And can see that whatever I produce here
39:07 the Axon Hillock is reproduced way down the acts on. In other
39:11 it's once it's been produced. It right? So if we did the
39:15 again and I said, Okay, the wave do the wave, you'd
39:18 two of them. All right, just happen. Let's add in that
39:22 one. So there's number three right . So here's one plus two plus
39:28 . You can see it's even So do you see this summation?
39:32 ? It's It's additive. Alright, not even saying what the magnitudes
39:36 but you add whatever the magnitude one to the magnitude of number two to
39:40 magnitude of number three, and all a sudden now you've got a very
39:44 , excited Torrey response, which results more time spent over threshold, more
39:50 I spent over threshold, the more potentials, I produce more action
39:54 I produced the MAWR that end up down the ax on so What we
39:59 here is we have a additive Yes, sir. Submission. Of
40:08 , That's a good question. Can wait until the next slide? He's
40:14 you can wait. All right, that's spatial. So you can see
40:21 these air different neurons or different pre cells producing their own E p s
40:27 and in that post synaptic cell, . So remember, e p s
40:30 is occurring in the post synaptic Alright, in response to its
40:34 So each of these individual cells are by space, and they're all producing
40:40 excited Torrey signal which results in three E p s PS. That when
40:44 together makes a large GPS p, is how we get those action
40:50 Let's look a temporal. All temporal, you're dealing with just one
40:56 . All right, so that's what is saying. It's like, all
40:58 , we're back toe. Just our , um, pre synaptic cell.
41:06 what we're gonna do is we're gonna the rate at which this thing is
41:10 , right? And if I increase rate at which I'm firing, it
41:13 I'm increasing the rate at which I'm neuro transmitter. If I'm increasing the
41:16 , which I'm releasing neurotransmitter, that there's march neuro transmitter out in that
41:21 cleft. I'm still trying to get of it as fast as I
41:24 but I'm overcoming that rate of termination so I can produce a larger eh
41:30 in other words, an additive effect that single one. So let's just
41:35 I have a magnitude For each PSP I produced. I get a magnitude
41:38 plus five million volts. So if do +123 quickly in succession, I'm
41:43 get five million volts plus five million plus five million volts altogether. So
41:47 getting a larger E p s PS 15 million volts. And if it's
41:53 enough so you can see how they're on top of each other because there's
41:57 refractory period, they just get bigger bigger. I could bring myself over
42:02 if I bring myself over threshold. produce action potentials for however long now
42:06 , the artists use three. It's necessarily going to be three. It
42:10 be one. It could be It could be 37 right? It's
42:13 the artist was making things confusing, to create a 1 to 1
42:17 That's usually not what happens. ma'am. Mhm. Well s.
42:28 let me let me try to demonstrate versus Spatial. All right, I'm
42:32 clap once. Now I want you clap with me. 123 All
42:37 Now you clap with us again. Now you. 123 Try again.
42:44 All right. Did the sound get and louder? Is each of us
42:47 ? That would be spatial. All , now, here's temporal.
42:50 keep in mind I'm not as good the picture. All right, So
42:57 one right rest, another one. ? But if I start bring things
43:02 together they started stacking on each right? So that's really what it
43:09 . It's not that I'm clapping It's just that the time in between
43:12 are getting smaller and smaller and So the answer to your question
43:17 could one neuron be firing more and frequently? Yes. And it could
43:22 be producing a much larger signal. the magnitude part. But it could
43:27 be working in conjunction with other neurons are producing their own signals, and
43:31 they're not acting as fast, But adding into that whole pool. Does
43:36 make sense for great? It's One second signals is able to.
43:53 , so remember s so I'm gonna the question here. So the question
43:57 , is it able to switch between two? There's no switching. It's
44:02 the timing, right? So special simply the fact that 22 things orm
44:07 are acting together temporal, as I , is basically that one neuron firing
44:13 a greater frequency. And so the to your question is, they don't
44:17 . They just do right. But might be observing spatial sub nation in
44:23 case. Or you might be observing summation in one case. Or you
44:28 be observing both occurring simultaneously. go ahead and ask your question.
44:37 also, Mason, because you temple into summation. No, no,
44:47 . So there there is no So there's no guarantee that any summation
44:55 result in an action potential. The time you're gonna get in action potentials
44:59 you get the the grand post synaptic above threshold. So you could literally
45:05 10 inputs that don't produce a strong signal to get to threshold so that
45:11 not the guarantee. The idea here how are we adding signals together?
45:14 really, really kind of the key . And if a neuron is firing
45:18 greater frequency in producing E P s , that would be unexamined of how
45:24 getting temporal sub nation. Because we're allowing the the post synaptic sell to
45:32 come back down to resting potential. just adding on top of the the
45:37 p S p that you just produced microsecond ago, right? And that's
45:42 you're seeing this kind of climb as as you're seeing there, whereas with
45:47 to I'm just gonna race all the on this slide here with regard to
45:52 right, What you're doing is you're in mawr and Mawr cells, each
45:58 their own e p S p. what you're doing with summation is you're
46:02 up the E P s PS that occurring simultaneously, So can you have
46:08 temporal? I'm just forget that multiple no, so temporal is always gonna
46:14 within a single neuron. All so it's it's increasing the rate of
46:19 in one neuron, whereas in spatial increasing the number of neurons firing
46:26 The difficulty in understanding these definitions is notice that both of them have a
46:32 of time in them. So special multiple cells firing at the same
46:37 That's not very helpful with temporal Temporal a cell single cell firing with greater
46:45 over a period of time. That's and that's where it gets kind
46:49 confusing. You're welcome. Got another online because hold on one second,
46:57 questions coming in, then we'll get you. Yeah, more except
47:05 Oh, so the question that's being is, What do I mean by
47:09 more time over threshold? All So if you watch that video in
47:13 the action potential, remember in action Onley produced once we open up all
47:18 channels and that occurs when a certain reached all right and it's it's kind
47:24 a chicken and egg thing, so don't wanna dive too deep in
47:27 but as long as your as your potential in your cell stays above
47:33 you're gonna be producing action potentials in words. You you can imagine action
47:37 being produced. I'm gonna try to this. All right, So here's
47:43 see. This is what I'm Here's my graph. Right here is
47:48 threshold. If I produce an action , once I hit that threshold,
47:54 getting my peak. So if I bring myself up to that threshold via
47:59 potentials, then as long as I'm that threshold, I will never come
48:04 down to rest. That doesn't I'll just keep doing that over and
48:08 and over again, all right. that's what this is trying to show
48:12 is like, Oh, look, reached threshold. So as long as
48:16 above that threshold for any period of , right? In other words,
48:19 long as the, uh, the is not allowed to come back down
48:23 rest, it will keep firing. it's above the threshold Now here I'm
48:30 the threshold for a longer period of . That's that's why you're getting multiple
48:34 potentials. And so there's still a period in there. The difference is
48:38 that I'm not allowing the cell to reach rest. The greater potential is
48:44 the the influx of sodium at such rate that the cell never comes down
48:49 rest. That's what is trying to . All right. Even though sell
48:52 to get the rest is not going It's kind of like having kids.
48:55 never gonna get rest ever again. , you had There's one more question
49:03 , and then we've got to get because we're getting stuck on some simple
49:06 here. Yes. So quick. eso the difference between no summation.
49:13 summation is basically the frequency at which when you're on is going through.
49:21 correct. That's all it iss You're . All right, So there was
49:26 question that came up a little bit and said Okay, well, what
49:29 ? If I have an e, s p n and I PSP
49:31 it is the same thing. This this is kindergarten math. Alright,
49:35 just gonna use kindergarten math as an . Well, and that's not kindergarten
49:38 grade math. All right, when start learning to add your numbers,
49:41 I take something, has a magnitude plus five and something has a magnitude
49:44 minus five. What is what happens I add those two things together.
49:51 get zero right, so they cancel other out. So this is what
49:55 when u V p FPs and I ps, they cancel each other
49:59 And so you can imagine I might some that's plus seven something that's minus
50:03 and then So now I have a in the membrane potential. That's plus
50:07 . That's still cancelation, right? just not a perfect cancelation. And
50:12 that's what cancelation is. It's simply an EP, ESPN and I PSP
50:16 against one another. And so you imagine if we went back to that
50:20 picture where I showed you that single with all these thousands of inputs,
50:24 some of them are E P s , and some of them are I
50:27 ps their dueling to determine what that of that cell is. All
50:32 because you're canceling out some of the . But again, going back to
50:37 stupid example of that poll on you ask your four million friends.
50:41 I break up with those people? know, the cruelty of the Internet
50:44 like 70% of them say yes, . And you're gonna do whatever they
50:49 because, well, you're getting your from Facebook, and what you're gonna
50:53 is you're gonna say OK, even 30% of the poll said no,
50:59 said yes. So that's enough to me over threshold to cause me to
51:05 my decision to dump my significant And that's really all thes cells,
51:10 doing other cells. Tell me what do. Other cells tell it what
51:15 do if the signal is strong enough reach threshold produced by action potential,
51:22 action potential. If the signal is strong enough, I don't reach
51:28 no action potential. I don't produce signal. Simple. All right,
51:37 what kind of synapses exist in the ? Lots of different types, the
51:41 common type, are the ones from on the dendrites. There's also what's
51:45 access Penis. We're not gonna spend lot of time talking about the spines
51:48 dendrites, but it's kind of a area. That's kind of like like
51:53 synapse, you know? I it's it's specialized toe, have receptors
51:57 stuff, but there's access Penis, then you can actually terminate on the
52:01 , so that would be a You could even have some that end
52:04 on the cell body. So you're even closer to the Axon hillock.
52:08 you could imagine those were probably pretty powerful. But the idea is,
52:12 , a zoo longtime stimulating, selling receiving side. Those are the most
52:16 types of synapses. So accident named for where you're doing access Penis
52:21 for where you're where you're connected, somatic, you know, Shaft
52:27 Okay, whatever. And then, course, because we can't just have
52:31 rules. We have to have complex you could have other ones that are
52:35 more complex. And these were like axle back sonic. And then the
52:39 weird ones, like the din drove . Those were like those space
52:42 uh, um, cells that don't axons, right? And then then
52:48 . But we're not gonna worry about . We just keep it simple for
52:51 , right? Act so dendritic Somatic access Penis are probably all you
52:58 to know. Now, just to that there are constants in life,
53:04 can also attenuate signals, just just axons can. Right? So if
53:11 have very, very small, thin thing, we have slower signals.
53:15 would be attenuation. Attenuation is um cancel or toe lower. That's
53:20 it means, right? So how I dendrite attenuate a signal, make
53:26 smaller, right, create greater That's the most common way. All
53:32 , so they have high resistance, current, so it's harder to get
53:34 signal down and this is just trying show you it's like, Look,
53:37 is the exact same strength Got a synaptic cell is producing a similar release
53:44 the amount of neuro transmitter. So you were to measure the E.
53:47 S P at the site of of exactly the same but because we're dealing
53:54 a smaller dendrite on the left side here. Okay, What we do
54:00 we can't produce an action potential, , because we have greater resistance,
54:07 we have lower current on the right side. However, we got a
54:12 , fat, juicy dendrite which allows greater flow of neurotransmitter, which means
54:18 we have really good responsiveness at the Hillock. Enough to produce an action
54:24 . So what we're seeing here is cells themselves can regulate how they're going
54:29 receive their signals. In other they can filter their own responsiveness.
54:35 of like you can on Facebook. that poll, I'm only gonna listen
54:39 my closest 200 million friends, right Lee. The ones that I actually
54:44 are the people I'm gonna pay attention , rather than all the people that
54:48 ever friended ever since the dawn of on the creation of Facebook or ticktock
54:56 whatever horrible thing you use now This kind of makes sense. So
55:01 not just in the axons that they regulate through the dendrites as well in
55:07 of size. Now the other thing , is that signals inside these
55:15 So remember cells or talking to other , And so that means you're
55:20 Imagine you all holding hands in You would be a network,
55:24 If you had more than two you could actually hold on to more
55:27 one people. And that's kind of these neurons do is they're interconnected with
55:31 another. And so information is being through these connections of who's telling what
55:37 do. And so these networks could either focus or they could be
55:42 Focused means they're confined us very specific . All right, so you can
55:47 a network, a signal comes in it works in a very specific location
55:50 get a specific result, right or we can say. It could be
55:56 the virgin. Other words. It signals to multiple places throughout the C
56:01 s so that you could get a spread response. Alright, again dumb
56:06 . Just so that you can see I'm referring to. Here. You
56:09 outside, you smell barbecue. First that signal goes to the amygdala.
56:15 you happy because barbecue is awesome, ? Even if you don't like barbecue
56:20 cooking meat for some reason, just people's mouths of water, right?
56:23 that would be another signal. Your begins toe water, right? And
56:27 do you do? You breathing more . You start walking faster,
56:32 All sorts of things. You start things like like piles of brisket because
56:38 Texas. This is the proper right? And so you can see
56:41 . This would be a divergent right? That that would be stimulating
56:48 systems so that you get a wider response. The thing is,
56:52 that for any sort of network, the number of inputs going in the
56:56 of outputs that air going out are limited. So notice if I smell
57:01 , I'm not gonna be stimulating systems have nothing to do with food,
57:08 ? I'm not gonna be making my work harder. My heart is not
57:11 be what my heart might be faster cause I'm excited. But you see
57:15 I'm trying to get at, And the other thing is, is
57:18 the more neurons you having a the greater number of synapses and there's
57:22 delay because that neuro transmitter when it's , is not actively seeking out its
57:27 . It's diffusing into that space. so there's a synaptic delay at each
57:34 . So if you have a single , it would be a very quick
57:37 because you just have the delay at one synapse. But if you have
57:40 synapses, you have tow add up that delay, which means you have
57:45 longer time for response. Now dumb example. This is not how
57:50 really works, but it helps you visualize it. You're walking in the
57:54 . You're looking at your phone because seen what you guys do. All
58:00 , car starts honking at you. do you do? Do you leap
58:04 of the way? No, it's brains. China process honking. Means
58:12 it a video game now is It's probably danger. I should probably
58:19 out where that danger is coming right? It's because your brains trying
58:23 figure it all out lots of as opposed to the fight or flight
58:27 , would be like a jump out the way told you of the terrible
58:35 . Now we like to think of York City's chemicals, these neurotransmitters being
58:39 and simple. The truth is, they're not. There's hundreds and hundreds
58:43 neurotransmitters. Spend your time just playing Wikipedia at the list of neurotransmitters that
58:49 and you'll become overwhelmed very, very , all right, but it's the
58:54 that that is our chemical. And what I first want to know is
58:57 we classify them based on their Alright, and I'm not again.
59:01 not gonna do not memorize these lists stuff. All right? I'm not
59:05 say the one that you should definitely know is to see the cooling.
59:10 , Okay, so let's see. calling is a neurotransmitter. Okay,
59:13 that's good. And then we'll look some very specific ones. Like the
59:16 A cola means we'll see. All , um, they are a type
59:20 mono. Mean, we got Where's my history? Down here.
59:26 , we have the amino acids. guys write about them. Those air
59:29 because they're specific to whether they're Torrey inhibitory. But you can see
59:34 other stuff that you probably never even about it being a neurotransmitter. We
59:37 about 80 p, for example, being involved in what energy? It's
59:43 80 p is energy. Whatever You know, you take a biology
59:46 , first thing, they drill in head, right? It's a neuro
59:50 . Well, well, great. you for confusing me, Dr
59:54 That's just one more thing to throw the pile of crap that I am
59:56 to be able to forget. And then we have other things.
60:00 gas is I mean, nitric oxide a neurotransmitter. Carbon monoxide is actually
60:07 neuro transmitter. Uh huh. I carbon monoxide was bad. Yes,
60:12 hemoglobin, Yes, but not for brain to use. And so you
60:17 see there's other things in here that a role in signaling. So what
60:22 want, you know, these are ones that I want you to
60:24 All right? I told you. the cooling. It could be
60:27 Torrey inhibitory depends on which system you're at. So today you don't need
60:30 know what that is for the You don't need to know which one
60:32 excited, Torrey or inhibitory. It's we talk about and say, Here's
60:36 seat of Colin. It's acting Torrey. That's where you go.
60:38 , this is what I put that market, all right? It is
60:43 own special category because it was the one discovered and nothing else is like
60:47 . It's like, great. And was just irritating thing. They were
60:51 , we discovered how nerves talk to other. We figured it all
60:54 Let's go look for things that look a set of coleene and nothing looks
60:58 it's gonna clean as far as all other Nero transmitters. Fine. Next
61:04 are the amino acids. What we've here is we've started off as an
61:08 acid. We've made some modifications. you guys are familiar with glutamate?
61:12 . You feel familiar with a spark ? I mean, if you've ever
61:16 your amino acid table at any point your life, you should go.
61:19 , I recognize this Spartak acid. , glycemic acid that you might see
61:24 on the table. Glycerine. You heard of right, you know.
61:28 . Those amino acids. Yes, also neurotransmitters. And then we have
61:32 , which is a modification of right? So glutamate and aspartame.
61:37 . Those are excited. Torrey gabba and glycerine are inhibitory nature.
61:42 whenever you see them, just put in those categories. Is excited.
61:45 , this is inhibitory these down We're gonna see frequently, Which is
61:50 I pulled him out. The biogenic . This includes histamine. You've heard
61:53 histamine, right? Primarily. Think in terms of allergies. When I
61:58 stopped up nose, I take a histamine. Alright. But that's not
62:04 only place where it is serotonin. heard of serotonin. Okay,
62:07 Um, cattle. Coleman you've probably heard of by itself. That's a
62:12 or category. But you've heard of and norepinephrine were really epinephrine. You
62:17 go. No, by another It's called adrenaline. That's epinephrine.
62:22 is its cousin. It's nor right? And so they're very closely
62:26 . What? They dio and You guys have heard off,
62:29 So these are the ones you should kind of. All right. I'm
62:33 be familiar with them because these are or useful neuro transmitters. Now,
62:39 I bring these up is because of I want to understand is that depending
62:43 what type of system you're looking these neurotransmitters can behave in either a
62:47 method, way or convergent. What means is divergent. Means is
62:51 if I bind to a specific receptor a specific cell, I'm gonna create
62:55 unique response. So I release and it acts on this selling on
62:59 Selling on this selling creates unique responses each of those cells. All
63:03 that'll be divergent. Con Virgin, the other hand, says I've got
63:06 cell and it doesn't matter which one these neuro transmitter binds to its own
63:12 because they always buy into their specific . But they work through a specific
63:16 and they produced the exact same So that means if I'm a cell
63:20 you give me dopamine, you give serotonin. You give me a seat
63:23 Colin. Doesn't matter. I'm gonna the same response because each of these
63:28 lead to that response. And what really telling you is that multiple systems
63:34 communicating with the cell through their own way of communication to produce the response
63:40 that particular cell so divergent versus conv means how creating these networks. How
63:47 I respond to a particular neurotransmitter? does the neurotransmitter that I release produce
63:53 specific response coming into the home Love only come into the home stretch
64:02 before test. It's like finally unburden . Now this is kind of a
64:10 way of regulating a signal. It's called pre synaptic inhibition and pre
64:17 facilitation again see big words easy to out, especially if you're a
64:23 But we are better than freshman, ? Everyone not your head to say
64:27 I'm better than a freshman. Even you're a freshman, Sam better than
64:31 freshman, right? And we look the word we say. Okay,
64:34 does pre synaptic mean? It's on the synapse. So it's acting.
64:40 is acting in the cell that is , and it says pre synaptic
64:45 So I'm inhibiting the pre synaptic cell facilitation. I am facilitating helping the
64:51 synaptic cell. And so in this , what I want you to
64:55 All right, we're gonna keep it , right? We can see over
64:58 . I have an exciting story. , right that excite or in your
65:02 would produce an E p S Right, So it produces an E
65:06 S p in there. There's my , which is strong enough that causes
65:10 action potential. The potential travels And you can see here that I
65:14 travel to three different pathways because I these different, um um branches.
65:24 blanking on the word right now. is the word. I'm looking for
65:27 different collaterals. And on each of , I have a cell that is
65:32 to that neuro transmitter. All so you can imagine I'm gonna stimulate
65:36 , so I'm gonna stimulate that. I'm going to stimulate that sell All
65:40 with pre synaptic inhibition. What I is that I have an inhibitory neuron
65:45 on one of those collaterals specifically right before it goes. And so what
65:51 basically saying is you're not allowed to whatever you do, do not release
65:56 neurotransmitter. So even though that that occurs and goes down that collateral,
66:04 inhibition prevents that cell from releasing its transmitter So the target cell gets no
66:13 . So I'm acting on which sell pre synaptic cell, right? So
66:18 would be the pre synaptic terminal right . What's happening in the post synaptic
66:23 ? Nothing, right, because it's inhibited. The pre synaptic inhibition effect
66:29 one? No, because it's not on that terminal. Does pre synaptic
66:34 work on that terminal? No, it's not acting on that terminal.
66:38 on Lee here at that one terminal that pre synaptic um, neuron is
66:49 . Let's flip it around. Gonna excite to sell? Well,
66:54 we're not going to excite the sell all. All right, just pretend
66:57 is no actual potential, no action being produced. So this cell has
67:01 response. This one would be no . This one will be no
67:05 This is not inhibitory neuron. now, this is an excited Torrey
67:09 . So this is an excited to on its stimulating that terminal. So
67:13 would we expect to happen in that self? You could say it
67:20 You get a response. So this is now firing. What's happening?
67:24 one is this one being stimulated? . Is this from being stimulated?
67:31 . So notice facilitation allows me to the pre synaptic cell in a very
67:38 manner to create a response in a synaptic cell. I don't have to
67:44 the whole cell stimulated. That's what and facilitation are. In essence,
67:51 basically turning on or turning off. this is doing so in a way
67:55 circumvents the normal pathways, right? working around. It's like asking your
68:02 to do something and she says And so you go ask your dad
68:05 telling your mom. And what does dad do? Sure. Go
68:08 You just worked around. Your mom work around the mom. Fifth,
68:19 neuro modulator is allowing us to change interaction between the pre synaptic still in
68:28 post synaptic sell. Now I mentioned that the communication between pre synaptic and
68:34 synaptic is one way you guys remember saying that that's what the neurotransmitter with
68:39 . What you're doing is the post cell releases a chemical that's not a
68:45 transmitter. Back to the pre synaptic or the post synaptic Selcan release a
68:53 back to itself or the pre synaptic release a different signal to the post
68:59 self. You see, there's a of communication going on or the pre
69:02 Selcan talk to itself. And what gonna do is it's going to change
69:06 relationship between the two cells. Give the example. Pre snapped cell post
69:13 self. This priest next cell releases molecules of neurotransmitter on the post synaptic
69:19 . We have five receptors, so basically a 1 to 1 ratio.
69:23 I want to increase the communication between two things, what can I
69:27 What are some of the things that could do to increase how much these
69:31 talk to each other. I got choices. I got neurotransmitter got
69:34 What can I do? I can either one. If I put more
69:39 transmitter, then this one is going respond more frequently because there's more neurotransmitters
69:44 the synapse. If I put more , there's a greater chance that neurotransmitters
69:48 find a receptor. So this is form of facilitation through modulation. How
69:54 I get more receptors? I send signals. Say, Hey, you
69:57 to make more receptors. Okay? do that. Send a signal back
70:00 the pre synaptic steps you need to more neurotransmitter. And that's what all
70:05 this is telling you. It's just you how we go about doing
70:08 All right, The signal is external the neurotransmitter. It's a unique
70:15 so I can increase the amount of transmitter, or I can decrease the
70:19 of neurotransmitter. If I'm inhibiting I can increase the amount of receptor
70:24 can decrease the amount of receptor, in doing so, I'm now changing
70:30 degree of communication between those two Does that make sense? Yeah.
70:40 . Now, typically, this is be done through g protein coupled
70:45 Now, I don't think this is significant. This slide, what I
70:51 to just kind of demonstrate to you that neurotransmitters air very, very
70:54 but one you start dealing with facilitation stuff like that. You start slowing
71:00 because there's modulation that's taking place. start slowing down. Um, the
71:06 in neurons to be clear. Remember two terms on a Tropic and Madaba
71:13 . Do you guys remember those two Very early on. I on a
71:17 basically says, I've got a channel opening and closing a channel to allow
71:21 to move in and out of the Meta. But Tropic says I've got
71:24 signaling cascade. I activate a receptor activates a cascade of events, all
71:30 , And so typically, I on on a tropic responses are very,
71:34 quick and short lived because all I'm is allowing, uh, ions to
71:38 through and I get a quick Basically, I'm just causing deep polarization
71:42 hyper polarization with Metta Tropic because everything already there. I'm basically activating,
71:49 I've got to turn a whole bunch different things on, so it takes
71:51 little bit longer than the neurotransmitter and we're not even talking about,
71:56 the the other type of signaling, is that long form of long distance
72:00 through nuclear receptors. All right, this doesn't even count. We're just
72:04 about within the context of a I can activate either a channel or
72:09 can activate a pathway. Now, of the things I could do with
72:13 pathways is I can actually activate It's just gonna take longer because I
72:18 work through that signaling cascade. So there on the far left side,
72:23 can see that would be an example an eye on a tropic.
72:27 Here's my neurotransmitter. I'm opening up channel. Things flow in, Get
72:31 quick response. Easy peasy right Look at the other one here.
72:39 binding. I activate, Activate something . And then that activation results in
72:46 activation of something else. So there's whole bunch of steps in here,
72:49 ? It's basically you do this and it's just a Siris of dominoes knocking
72:53 other open. So finally, at end of the Domino chain, I've
72:56 a channel so I can still get eye on a tropic response. It
73:01 is a result of meta but tropic . Look at this one. Do
73:07 think this occurs much, Much, later? Well, let's take a
73:15 . Here's number one. There's number . Number two is going over
73:19 right? But number two causes the of this. So there's number
73:23 There's my cycle of K and It binds there. There's number five
73:26 finally I fost for late this thing that's opening up the channel.
73:31 in this case, potassium is moving . Oh my goodness. That's like
73:35 seconds later, you know, as to instantaneous. And remember, in
73:42 cell milliseconds count. Very quick Very slow response. Now glutamate receptors
73:55 this alright, glutamate receptors. glutamate is an exciting torrey neurotransmitter.
74:02 can act through a G protein coupled . We refer to this as M
74:07 . All right, so metta tropic receptor. That's where the name comes
74:12 so it can act through meta But typically what we use is we're
74:16 be looking at I on a tropic . The most common type is the
74:20 . A receptor. It's a very fast response, right. What
74:23 see here is we see the glutamate binds to the ample receptor. It's
74:28 sodium channel. When it opens sodium comes in and it gets
74:33 very excited, excited and happy. right, great, wonderful. Some
74:38 also leaves some calcium moves as But the other thing that happens if
74:43 produce enough glutamate, what's gonna happen that you're gonna cause this cell to
74:48 polarize and that deep polarization results in change in the shape of the NMDA
74:58 . Now, glue to make also an M d a. And it's
75:01 channel. But it's a channel that open unless it has been modified.
75:07 so what happens is is, if produce enough glutamate, you're gonna open
75:10 the AM pose, which causes the B a receptor open up. So
75:13 you've got two channels, and now getting an even greater deep polarization.
75:17 a slower response, but you get much larger response as a result of
75:23 activity, and then they have a type. What's called the kind
75:28 Um, these could be found on synaptic cells. So you can imagine
75:31 play a role in how much glutamate gonna release. So if I want
75:36 release a lot of glutamate, why I just tell the cell?
75:40 by the way, I want you release more glutamate. So I bind
75:43 the receptor glue that binds to itself creates a positive feedback loop just as
75:48 example. What we're talking about here basically causing cells to have different
75:58 What is referred to as plasticity? means changeable. All right. Doesn't
76:05 Barbie doll means changeable. All The nervous system is plastic, all
76:13 ? And what this is showing you this particular examples here is an
76:17 Neuron. Alright. And what this does is when it's stimulated, releases
76:20 certain amount of neurotransmitter, right? I stimulate the cell on a regular
76:27 because a certain amount of neuro transmitter be released if I stimulate the cell
76:33 , how do I get a bigger ? Well, I can't release the
76:35 amount of neurotransmitter gotta release more, in fact I can't produce more.
76:39 so instead, I'm gonna produce two types of neurotransmitters. Most cells do
76:44 at least two different types of so they have a slow signal
76:50 and then they have a large signal . And that's what this is showing
76:53 is like top. There's your low stimulation. I'm just releasing with one
76:59 down here in the bottom, I'm all sorts of stuff, and as
77:02 result, I get a much bigger . This is a plastic response I'm
77:09 not dependent upon, you know, stimulation to cause more neurotransmitter. I'm
77:15 able to change how that neurotransmitter that neuron behaves in response to the type
77:21 stimulation it gets. I know we're down to the wire here. For
77:27 of you who are paying attention at , I got two slides. I
77:30 we'll stick through the entire to slide I really don't feel like recording
77:33 Anything else do you guys feel like recording two slides with the material?
77:37 just want me to just shut up get it done so neurons can be
77:44 in how they produce their signals. much you know, Transmitted released.
77:49 sort of response? To give, they respond. So one of the
77:52 that we can respond is we can our responsiveness to the type of signals
77:58 we're getting. We have terms for . So up there at the top
78:01 the graph, it's showing you the red lines represent action potentials,
78:06 It's saying this is the rate at action potentials are acting on this
78:11 Right? So here's the stimulation. how do I respond to that?
78:16 , over time I get really sick tired of being stimulated the exact same
78:20 . So do I respond the same ? Put another way, your sibling
78:25 poking you in the head over and and over again. Now, this
78:30 just part of your life. How you respond to the first time you
78:33 really kind of irritated, like Stop right. But they're bigger than
78:38 You're the younger sibling. In this , you can't do anything. So
78:42 a while, it's just okay. is how I live Now you become
78:49 , right? That's what happened. see the synaptic strength, it's basically
78:56 going down and down and down because amount of stimulation isn't enough to get
79:00 rise out of you anymore. All , That's the example there.
79:05 How did they figure this stuff This is the fun stuff. I
79:08 you guys want to get out They started with slugs, right?
79:12 they would tap on there. I . All right, These air sea
79:15 . So they're big slugs and you their Istock. What would a flood
79:18 when you tap its Istock? Suck right in, right. And then
79:22 would cautiously put that stock right back of it. You smack it
79:26 it would suck it out. And keep doing it after a while.
79:28 just like Okay, I guess this the way I live now it's become
79:33 pichu. Waited. All right. there are different ways you can see
79:38 terms of increasing synaptic strength. You see here, here's my pulses.
79:42 then I have a Siris of strong in a row. Facilitation. Look
79:46 happens. Boom ! My response is goes way, way, way up
79:50 response to the action potentials. But , Dan, it comes as soon
79:54 the stimulation ends. So I'm responding mawr strongly in facilitation. Potentially ation
80:03 outlast the stimulation, so it rises response to the increase in the action
80:08 . But you get a maintained so it's occurring even beyond that,
80:17 ? Basically, you ramped up your , and so even though the signaling
80:21 down, you're still over responding to initial, um, period of
80:30 Depression is just kind of the reverse potentiality shin. All right,
80:35 um e don't have a picture of here, but it zits another form
80:41 plasticity showing a much larger response. why do we care about this?
80:46 is the last slide. And why these things up? First off,
80:48 want to understand. The nervous system plastic. It changes its malleable relative
80:54 the type of signaling and type of . And you should kind of already
80:58 this, that you are capable of . Are you guys capable of change
81:01 u mass squares in my classroom? . All right, so change.
81:08 your body changes in response to new . But what's really interesting is this
81:14 how our brain deals with learning. changes the interactions between cells through what
81:21 called long term potentially ation. A term depression, right? In other
81:26 , it changes the response between the and maintains that change. And this
81:32 how we hold on to information. interactions between those cells is gonna be
81:39 . So this is what a memory . Did you guys ever see the
81:42 can never remember The name is the spotless Mind movie with, um
81:49 thank you, Jim Carrey. Where was. Basically he and his girlfriend
81:52 up there trying to race their And so it's this idea of going
81:56 and this cell holds a memory. not how memory is held. A
82:00 is really a Siris of neurons interconnected each other, firing at a specific
82:07 in a specific rate in the specific . Right? So when you make
82:11 experience, you actually create that signal what your body does is it keeps
82:17 it, modifying the interactions. for example, if I'm a neuron
82:21 I'm interacting with these two neurons and create something that potentially, it's
82:26 but depress is here, I may , over time withdraw my interaction with
82:30 neuron where I'm depressed and reinforce that . And now I've created a new
82:39 . This is how the nervous system . It's plastic, and so that
82:44 done for the exam. What were ? You're like What? Yeah,
82:51 for the exams. Exam is on , right? What you need to
82:56 is everything we've talked up to this , all right? Most of the
83:00 is baseline information that we're gonna be . Moving forward. That doesn't mean
83:04 all knowledge stuff. It's basically how I going to use this stuff?
83:08 do these terms mean, Right, then how are they applicable? There
83:12 some application type stuff on example. all multiple choice. For those of
83:18 who are wondering, Do you have show up to class now? You
83:22 at home, take your test, Big Brother watch you show off your
83:28 or whatever your spaces. If you to take it at McDonald's or
83:32 that's cool. To free WiFi, still have to wear a mask.
83:35 sure there any questions Online? All right, One second we got
83:44 question was how many questions. There 50 questions over the 60 minute
83:48 It's a 60 minute exam. It's an hour and a half, so
83:51 get to be done. Most people exam between 45 50 minutes. So
83:56 It's not like brutal average on the , typically in a typical semester is
84:02 us five. I'm shooting for I designed the exam that way.
84:05 don't panic if you're like that's what shooting for an average. Alright,
84:10 you're used to seeing 75 eighties. , we're trying to challenge you
84:16 but that also means there's a That's right, because hundreds don't tell
84:21 anything about you. Sixties. Tell something about what you've learned. What
84:25 have. Let me answer the question . Then go ahead. My
84:33 Go ahead. How so? What need to remember? Is that an
84:48 , the action potential that we are . So it depends on how you're
84:51 this question. So remember the action is the signal in the post synaptic
84:56 that causes the release of neuro That neurotransmitter results in the E p
85:01 P or the I P S p the priest or excuse me in the
85:06 synaptic self so action potential is in pre synaptic cell and is being resulting
85:11 the E P S P R i s p and post synaptic so one
85:15 to the next. But the E s ps and the I PS ps
85:20 added together in the post synaptic cell you can now call that post synaptic
85:26 the next pre synaptic self. And in the next cell, you're trying
85:30 stimulate the next cell down the So the E p s ps that
85:33 producing in the post synaptic cell if great enough, they can overcome threshold
85:38 caused the action potential. So what looking at here is basically kind of
85:42 doe I produce an action potential that in the production of a neurotransmitter that
85:47 in a response in the post synaptic . And then what does that response
85:51 do? Well, it resulted another potential which stimulates the next cell down
85:56 line in the same exact way. that kind of makes sense. Did
85:59 answer the question or did I kind circumvent? Yeah. Okay.
86:05 Thank you. Another question online, heard. Yes, yes. So
86:13 see right now The time is I even see. It's 2 27.
86:17 2 30 the practice exams are My practice exams Remember our questions.
86:23 have thrown off the exam. All . In other words, I don't
86:27 they're useful questions anymore. But what does do is it allows you to
86:31 how I write a question. Does kind of makes sense? So in
86:35 words, don't rely on content reliant how does he ask questions so that
86:39 can see that I do not write trying to trick you. That's why
86:44 want you to be a confident I'm trying to test whether or not
86:47 learned what I taught you and whether learn how to apply that information.
86:52 not looking for ways to screw your . If I want to write a
86:54 that screwed your world, I could that and you could do the same
86:58 for me. We could literally out one another, and you could prove
87:01 I'm an idiot and I could prove you're an idiot and we walk out
87:04 here going well, who team of All right, because there's lots of
87:09 in the world that I don't but the goal of an exam.
87:14 right. And this is really important the who have test anxiety. The
87:18 of the oven exam is not to to find out what type of person
87:22 are, but we kind of equate right. If I don't do well
87:26 tests, it must mean I'm That's not what it means. It
87:29 Did you or did you not learn information? All right, So if
87:33 worried, ask yourself. Have I the information, and if you've learned
87:37 information, you're J all right? I'm not trying to find ways to
87:42 it difficult for you. I'm just to see Did you learn this
87:46 All right. And nine times out 10 things, my favorite part about
87:49 a professor, you know, students to my office. I mean,
87:53 really do that now, but and be like, I don't understand how
87:57 missed this question. And I'll sit , you know, kind of
87:59 let him calm down. Let's walk it. And they're just like I
88:03 believe I missed that. I can't I missed that. I can't believe
88:06 has to do with how you're studying you're retaining information. So if you
88:10 how to study and hold on you're gonna be fine. Because,
88:14 I said, I don't write trick . I'm not sitting there trying to
88:17 how can I make you get, know, make this one question so
88:22 everyone is No, no, that's the goal, all right? It's
88:26 hard to write test questions like Well, I guess it's not,
88:30 I don't see the point in And then the other half of that
88:33 was it was practice exam, uh right. So the best way
88:40 kind of figure out what's gonna be the exam is everything I talked about
88:44 the class or really in the video well. Anything that's on the slides
88:48 fair game. So I'm not gonna for some obscure fact that's in the
88:52 , because I know it's dense and and it goes beyond much of the
88:56 that we think I think is important junior level class. So you rely
89:01 the power points that your baseline, there's something in the power points that
89:05 don't quite get. It's like I'm gonna use an example. I don't
89:10 this potentially ation versus depression or, , thing We'll go to the book
89:15 see if it does a better job explaining it to you than I did
89:19 the three minutes that I produced the about it in class. Alright,
89:23 allows you to slow things down. of think about it. Look at
89:27 examples, you know, and see that helps you. But I'm not
89:31 pull random stuff from the textbook, right? Because that that that could
89:36 devastating. I don't even know stuff the textbook. Right? So notes
89:43 book to supplement anything else, Yes. Eso with regard to temporal
89:59 spatial submission, remember, with temporal , your your decreasing the amount of
90:04 that a single neuron is firing so you're not allowing the cell to come
90:09 rest. So that means you're getting and closer to threshold. The more
90:14 Lee you're firing. All right, let me just back up so you
90:18 see the picture here. For those you who are looking for it.
90:21 guys don't have to stick around if have someplace to go. I'm just
90:24 try to finish answering these questions. we go. Alright. So if
90:30 time between each of the subsequent, , neurons firing get smaller and smaller
90:36 smaller, that means your signals are closer and closer together. Which means
90:40 never allowing yourself to come to which allows you to reach threshold.
90:44 right. Spatial summation, on the hand, is more than one neuron
90:50 at the same time. So the neurons firing at the same time,
90:52 bigger the signals that it's going to together, right? It's standing on
90:57 of each other's shoulders, do that of makes sense. Sort of.
91:04 , all right, But okay, , give mhm life. Right.
91:21 , you know, I've been looking the test. So there there are
91:24 specific things that you probably should like, not specific pathways, you
91:30 , like, what does this pathway like? But maybe what you should
91:34 . I mean, because I know do ask questions like, you
91:37 what would be in effect, er this type of G protein coupled
91:41 I might give you a list of , right? So, for
91:45 a an example of a transducer in G protein coupled receptor pathway would be
91:50 G alfa protein or the G You know, that would be the
91:54 , I might say. Okay, the Cal module in pathway, what
91:58 be the second messenger? All that would be calcium. Alright.
92:03 looking at those pathways, um, specific ones we looked and there
92:07 like, two major ones. And like, a third one. That's
92:10 of a minor one. If you of look at those and understand kind
92:13 understand, that's great. But I'm gonna ask you. Here's the insulin
92:17 , you know? How does insulin ? We've never talked about it because
92:20 that zit was just not something that think is important at this point.
92:25 . But at the same time, also talked about hormones, right?
92:29 I showed you the hormones of the hormones of the pituitary glands.
92:34 I would know what's regulating what know coming from the hypothalamus, know what's
92:38 the anterior pituitary and how they're being , because that's something that is,
92:43 not hard. It's actually fairly But at the same time, if
92:47 haven't looked at it, you're not connect those dots right? So you'd
92:51 like, Okay. Thyroid stimulating hormone produced in the anterior pituitary. It's
92:56 on the thyroid gland to produce thyroid , but it's being regulated by thyroid
93:02 releasing hormone from the hypothalamus and knowing three of those you know is
93:09 I'm not asking. What does it at the very end, right?
93:12 does thyroid hormone do? We didn't about that. We'll get to that
93:15 . But I figured it be better get this portion of hormones out of
93:19 way. So I would know those specific pathways for the hypothalamus, the
93:25 gland, and, um, what target tissue is. Yes,
93:35 Are the quiz questions applicable to So all right, So the question
93:42 , are the are the quizzes helpful terms of how the how to prepare
93:45 the test. So I would say air how I write questions. So
93:49 already kind of experiencing that? But I would call those would be very
93:52 steak type questions in other words, basic knowledge questions. I might be
93:57 you to to be more applicable in of the knowledge. So I may
94:02 , Well, why? I will you knowledge question. It's the only
94:04 we could get ourselves buffered, So if you think of a
94:07 you know, if I want to an average in a certain way,
94:09 got to give you guys easy questions get everybody to a certain threshold,
94:14 ? And then after that, that's the hard questions come in. It's
94:16 , How do I separate out the student from the B students from the
94:19 students? That's where the hard questions in. So I would say maybe
94:23 of exams are, like, like the quiz quizzes are. But
94:27 after that, that's when it's going be more like, Okay, here's
94:30 situation. What do you expect to based on what you've learned? All
94:36 . And those shouldn't be hard if understand conceptually what what we've been talking
94:42 then, that it won't be Um, there's some that are you
94:47 look and go What the hell, there's like one or two of
94:51 Alright? And those were really the the best way I know I would
94:59 use this quiz is kind of as framework of is this material that I
95:03 , right? So the best way think again is to study is to
95:06 of look at what was this lecture ? What was I trying to
95:09 And that's kind of the big And then from there, you kind
95:12 say All right, so if I trying to learn X what is x
95:16 of? Well, there's x one two x three x four x five
95:19 are the the learning objectives. Eso for like today's class would say
95:24 we're trying to learn. What? trying to learn the synapse,
95:27 We're trying to learn how, uh p s ps and I ps
95:32 You know, we're looking at potentially . In other words, you
95:34 the plasticity of cells and so you of use those this kind of that
95:38 umbrella And then what you do is kind of distinguish what makes this different
95:41 that. So why is an P s p different than an I
95:44 s p different than a GPS P are they? So that's kind of
95:47 definition levels, and you say well, how do I produce any
95:51 ? How do you know? So kind of give you more of a
95:55 edge is like Okay, so if increase number of action potentials that air
95:59 E p s PS, what would expect to happen to the G
96:02 S P? That's a simple question you can probably answer. That's not
96:07 a I memorized the fact and vomited answer, And that's where I'm trying
96:10 get you guys going to is that less of the, you know,
96:14 me vomit, memorized fax All But I don't think you'll notice the
96:20 . I mean, it's it's hard tell when you're taking the test,
96:24 you know, when you're writing, like, Oh, these are
96:27 memorize this fact. Here's the Any other questions online? I hope
96:31 answered the question. Okay, they don't have to being There is
96:40 pictures on the exams, so anything you're gonna have to require from a
96:45 will have to be learned and stored memory. Right? So the idea
96:50 like, right now I'm not looking . But could you could you draw
96:53 and envision what a G protein coupled pathway would look like through a,
96:59 , you know, you know, would a second messenger system look
97:02 And if you could mentally draw that's that's a good thing, because
97:06 not gonna give you a picture and , Identify the transducer. I want
97:09 to think about What is that? does this look like to me?
97:13 that's knowledge that's storing information. I I answered that question thing.
97:20 you have to know, Major. . I mean, if that was
97:25 question, Do I need to know pathways? The two big ones?
97:28 talked about the the protein kind of cyclic amp pathway, the Kalamazoo calcium
97:33 module in pathway. Those are the big ones. And then beyond
97:37 I'm not asking anything. No. , no, because muscles do not
97:54 using special summation. All right, , The answer is to that question
98:01 , which we haven't talked about They ah, single muscle fiber is
98:06 by a single neuron. So if want to get a muscle to
98:10 in other words, to produce a , what you need to do is
98:14 need to temporarily temporally some eight. other words, increased the number of
98:20 stimulating that neuron, resulting in a and stronger twitch, which will result
98:25 in tetanus. All right, so not too neurons. It's one
98:29 so you can never have spatial summation a muscle. I hope that answered
98:36 question. Anything else? All let's go home and have a good
98:44 . Who thank you for showing
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