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BIOL 4315/6315 Neuroscience (21592) - NEURO 2020 EXAM I REVIEW SESSION Tue-Th
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00:00 mhm. So this is a review for exam one. This is for
00:06 and Thursday Class, and your exam be on Tuesday. Okay, coming
00:13 on Tuesday at Casa. But this session was recorded yesterday, and it
00:19 really, I think very good. I will proceed with playing this for
00:25 live, and I will take questions each subsection that we've discussed. And
00:34 after the entire review, the first that I showed him. And I'm
00:41 remember to try to show you the each review session for each exam.
00:48 reason for it is I want you look at the slide and see what
00:53 knew, Uh, in the end August And what you know now that
00:59 this September. And I think that you're looking at neurons and synapses and
01:06 , you're starting to understand the anatomy these narrows anatomy of the surrounding wheel
01:12 , how they form these networks different sometimes of cells. Then you're
01:18 the right track. And so I'm walk you through some of the material
01:22 we covered again. This is not say that only the material that I
01:27 . You can ask any questions during session from any material. I would
01:32 that I really would like to say there is sort of the introduction section
01:39 these in these eight electricity can be up into introduction and history of
01:46 The second section is neurons and understanding neurons and glia. And the
01:52 section of this first exam is what action potential and understanding the Channel kinetics
02:02 some of the physics that go behind understanding the actual production. Okay,
02:08 what I'll do is I'll walk. Thio sort of the history key elements
02:15 and take a short pause, maybe 15 minutes into it. Have you
02:20 new opportunity to ask questions, So now when we started talking about
02:28 , this is a reminder of your that is essentially the material and electoral
02:36 it. We talked about prehistoric times brain Trumper nations to recall why they
02:41 done. Recall that they were found the world and in many different
02:48 Then we then talked about in the that was a part of the And
02:54 Smith Surgical Papyrus, where he detailed head traumas and the thinking. If
03:00 introduce about medicine, the brain and diesel effects off the brain that can
03:07 seen in the periphery at the same . Still, considering heart is the
03:12 important work and where the switch starts place with Hippocrates, the modern father
03:17 medicine. Remember, we talked about of believing that the brain that's the
03:24 important center and during the Dark Ages is, ah, lack of
03:30 although there is a lot off during period, we talked about gallon,
03:38 , that he worked with, um was a part of the gladiator scene
03:45 he was able to access and he dissecting pigs and sort of his thinking
03:52 until the Renaissance. Interest in the . Questioning gallons, anatomical descriptions and
03:59 and standing off ventricles thinking that ventricle very important distinguishing between gray and white
04:09 . There's ecology side. We have a card who initiates the reflex theory
04:16 also talks about this connection between the brain deterred or sum. I think
04:23 I am which I often like to I eat. Therefore I think
04:29 Be careful what you eat because I influence. How do you think?
04:33 he is in the Western mind body , which is also not in
04:39 This will take me out of parts the world at the same time.
04:42 on to something, thinking it's a , mechanical theory thinking that's influence
04:48 maybe from the ventricles pumping some sort information through the pipes into the muscles
04:54 move muscles. And we should go lot of using by electricity than confirms
05:00 nerves or not, hives for channels electricity. Call this and we talked
05:07 major parts of where this electricity and chemical transmission would be dating. Place
05:13 the central nervous system and the peripheral system. CNS is a serene,
05:18 served our brain stem, part of brain spinal cord adores from brain stem
05:24 vertebra and then has a spine owners off the spinal cord or superficial nervous
05:32 . Sympathetic and parasympathetic, which we really studying. This course, the
05:37 lobes of the brain, the frontal focus separating it from the parietal of
05:43 back of the brain, like several Soviet fishery or separating the temporal of
05:48 back of the brain and cerebellum. little brain is illustrated here is
05:53 so we now know that these loads very different functions. We talked about
05:58 anatomy off the spinal nerves, and know now a lot more about
06:03 We said that there's a dorsal component now. No, the dorsal component
06:08 so we can themselves who need Holder creases blew the named and it takes
06:13 signal from the periphery. And it's the travels of those final chord.
06:17 from there it actually is motor neural motor neural something Eastern back because muscle
06:26 of construction by releasing its Alcoa or colon, I say the South Col
06:32 arsenal color. I don't know why the same thing. It's a little
06:35 . Uh, Then we talked about , and we said, You
06:39 it was really important to start understanding parts of the prayer not responsible for
06:44 functions. So Joseph Yao, sort main character orphan ologists. He was
06:51 standing that you could understand the functions the brand by reading the cover off
06:58 book by reading. This calls indentations of protections on the phones itself.
07:05 the skull to determine how different psychological tendencies and innate features were reflected
07:13 you within you as an individual. combination of, I would say superficial
07:20 and psychology. Really, that's that's Zeins They're onto something. But not
07:27 brokers discovers that broke us area. spot here. You had a home
07:34 question which numbers? Broca's area. numbers is Vernon? This area is
07:39 that home or question? Uh, . And when I say which which
07:47 area is as it relates to Brockman broken determined specifically, this part of
07:53 brain is responsible for expressing the We talked about perceptive in Asia,
07:57 would be damage to learn in this and most difficulty understanding a ribbon language
08:05 word. And then we talk about condition invasion, global invasion.
08:10 please remove these and engage one of most famous characters in neuroscience. Can't
08:17 . I can't forget this person can't this guy he couldn't remember certain,
08:22 had an injury in his hand. Aziz, you recall this was a
08:28 that you could have a pretty pretty massive injury to the head, but
08:34 you don't lose all over the It's not like all of your functions
08:38 impaired all of a sudden to certain . It's specific, you know,
08:42 functions are lost, illustrating to us damage to the envelope was also responsible
08:48 controlling executive functions and aggression, which turned out to be quite aggressive.
08:53 to some of the accounts following the , Charles Darwin introduces the spirit of
09:00 that the environment shapes us. It our organs and it shapes the structures
09:05 our brain. It shapes that these the finches it shapes the behavior and
09:13 of the turtles. External anatomy. we look inside the brain. We
09:19 see them. We have very specific what we call cortical map cortical features
09:25 critical mass that represent organs are important us. And the organs are important
09:31 us, such as eyes such as . We will have very complex maps
09:37 representations in the cortex or other So just rats whisk oring and sniffing
09:44 . This importance of rats would have whisker map represented in their somatic sensory
09:50 , which is really adaptations in their where they have to do, which
09:54 evolutionarily or blacker than that evolution off brain structures and reshaping of these critical
10:01 . It is currently happening to us we speak as well. Okay,
10:05 I would say that this kind of the first, uh, section off
10:10 first off this three sections that I'm talk about. I'm going to movinto
10:17 and glia. Unless there are questions you can amuse yourself, you can
10:22 the question. You can also write question. What was questions and in
10:35 chart? Yes, that s We continue on nuke ourselves. Just
10:47 know which of the brain matter that think was for learning white or
10:56 in which actually is more associated with ? Yes. So it's not that
11:05 that point that they actually contemplated. Ah, which part is that?
11:14 need all of the parts of the matter. The Selma's signals air carried
11:18 the white matter by the processes. processes connect the cells and established communication
11:25 neurons and network. So you need activity. All of it is activity
11:29 process. You need all of the for learning. But the where that
11:37 is stored Now that's a really good . Actually. Know that memory and
11:42 in general memories air widely distributed throughout brain. So, um, what
11:51 with my camera? So, you you do have widely distributed throughout
12:02 brain storage of memory and different tasks you recall. And there are certain
12:10 and pathways through which you can recall memories and tasks. But at their
12:18 , what they were kind of looking is quite rudimentary. When you think
12:26 brain out of the skull, the matter, which is cerebral cortex on
12:33 the top on the surface, off off the brain, it's softer and
12:39 sants the white matter because they're Meilin , and they're kind of a bundles
12:44 , insulated wires running together. They're , and this rudimentary soft versus hard
12:55 them partially that the soft part, is the gray matter. It's sort
13:01 like a sponge because it's soft, can squish it. Therefore, maybe
13:07 where stuff gets absorbed, and the part is not a squishy, so
13:14 serves a different function. Maybe it to squishy parts or something like
13:18 That's that's That's what they were postulating that. So thank you for the
13:22 . And I hope that clarifies So let me see. Uh,
13:28 is pretty basic sections. So if is no further questions, I'm gonna
13:33 the recording for a second and then on to the second section of that
13:41 going on. They're on. Julia thio These guys here and we
13:48 about neurons and glia. We talked these very important players. We talked
13:54 the bank that visualized there is properly need microscopes, and you needed
13:59 So know your stains, because the in the brain is mostly and the
14:09 So what stains and we're talking We're talking about gold to stain.
14:15 , uh, one of the features gorgeous Um, let me think.
14:21 only see a fraction of neurons. small fraction of neurons. A few
14:26 , uh, absorb the stain. when exposed, you can expose Not
14:32 there's so much, but the process September is the accents. And this
14:36 , really in Spanish Neurosciences ceremony, was responsible for making these amazing drawings
14:45 neuronal circuits and insightful on believing in doctrine, as opposed to the particular
14:53 . And this gentleman on the bottom rice search all sharing toe later was
14:59 for planning terms. Synapse describing what happening at the synapses specialized connection between
15:06 neurons. Okay, their anatomy and morphology. Using histology so astrology,
15:13 air histological stands and later we developed histological states using, you know,
15:19 , chemistry. Eso these stains This Golgi stain was incredibly important for
15:27 development in history of neuroscience. Of three people, you should know all
15:32 them receiving noble prices. Missile What's the difference? It stains all
15:37 the cells, but it doesn't stay the process is very well. They
15:40 you to distinguish between glia and but it is mostly for the side
15:44 architectural was so most of the stacking these cells architecture of the site of
15:51 , of cells. So using this stain, it has your opinion.
15:56 , who used the stain and identified these different areas based on the structure
16:04 correct correct correct heuristic arrangements off cell and their directionality uh, the cell
16:14 being arranged using in missile stains. this is where you would get
16:17 So from Focus and Veronica's Area. we developed electron microscopes standard, like
16:25 were not able to visualize synopsis. microscopes were able to visualize synapse anna
16:31 resolution synapses about 20 nanometers in And so we discuss it. Now
16:36 can see individual synapses to withdraw. only 10 drives put these communiqu spines
16:42 the Boston African the pre synaptic German entering on these post synaptic communiqu
16:48 And we started introducing this idea that spines are actually plastic. And so
16:53 your electric supporting materials, you a lot See that there's a article
16:57 for yourself enhancement, your knowledge, enhancement on the drink plasticity, especially
17:05 you're a graduate student. You may look at that article now. This
17:10 , uh, recordings that we can now without stains, the natural infrared
17:15 recordings that allow us to visualize neurons the form electrophysiology. Later, we
17:20 about how these Electra's we can form types of electric physiological recordings, uses
17:28 clamp recordings, and this is exactly status that you would see their computer
17:33 , single electric controlled voltage clamp recording wholesale ash clamp recordings that we discussed
17:40 question on this question course. The of the brain is that we have
17:46 serious processing and in parallel in serious , that from periphery, from the
17:53 stimulation from peripheral organs such as visions as years or so, we started
18:01 increasingly forming a more complex and more understanding of the sensor information through the
18:10 in Siris. But in parallel, process information that there's a redundancy,
18:15 that's really for protection off the We talked about the current view,
18:20 different surfaces this again starts relating to and these different experience and neuron.
18:25 it's quite we need, causing the and also lighting up different parts of
18:31 brain as we discussed. And uh, and also having an ability
18:36 track single cell, single synapses and single molecules in this age. So
18:43 think maybe this could be there. I may have been spoken earlier when
18:47 had that neurons and glia slide, cannot there. That's what I wanted
18:52 get toe. So these were some the basic things and learn some way
18:55 we talked about and internally the transcription . We describe this, you know
19:01 was genomic era Michael Race and how done to study changes across many different
19:09 . Thousands of genes and different brain or different brains and infected or diseased
19:16 versus normal brains. Organelles that are basic and you'll find it anywhere.
19:21 . P Brain consumes a lot of . This is this is something really
19:27 to think about. The brain consumes 20% of the total body energy,
19:36 of the total body energy. The weighs only about £3.5. You do
19:42 calculation. What percentage of the total weight that is So the brain is
19:48 system that consumes a lot of energy the system is driven. Anamika
19:52 That's a nonlinear dynamic system plastic And that plasticity in the dendritic spines
20:01 the structure is in part due to fact that you have to do.
20:05 was a model you have Cody instead moving with this and we watch the
20:10 , including was a model with the membrane, and you have a supporting
20:16 of skeletal structure underneath to recall the tubules, federal film and so micro
20:22 and then you have micro tubules that important for transporting that you can
20:27 um, compared micro tubular transport and disease of interest that we discussed on
20:33 . The smallest on an active elements be found in the most peripheral distance
20:38 of the South because they can reshape . And they can also change the
20:44 anatomy of that experience collapsing 100 expires protrude them all together and such.
20:52 , uh, I'm gonna go really about the hallmarks of all Thomas
21:01 Uh, the reason for it. we discussed it here. So is
21:07 for for a number of reasons. let's review you a list off neurological
21:14 that we discussed so far. But of the things that we have to
21:19 so Alzheimer's disease talked about hallmarks of brain, talked about the plaques,
21:26 plaques or beta amyloid plaques. We about how protein tangles, and we
21:32 that these tangles and tangled up our to be the highway so caring transport
21:38 , the communication between the cells and plaques cam impinge on black salons and
21:43 on the synapses and essentially caused uh, areas that are calcified and
21:51 inflamed on the brain. So this the pathology of Alzheimer's that we talked
21:56 the symptomology about Alzheimer's that we talked the early stages would be a short
22:02 memory loss and anxiety in particular. almost a few of us eso we
22:10 this slide, okay, I'm gonna back and share that on a
22:19 Once after Alzheimer's disease, we talked den drives and accents and we describe
22:26 . We talked about external transport. between the territory, transport from the
22:32 into the periphery, about max on , from the distal ins for free
22:38 the Selma. Alright, Angel's for . In essence, funds are a
22:42 dynamic for retrograde transport that uses things with you girls is the highway
22:47 So if you tangle it up pretty news. Retrograde transport tracers. Now
22:53 can use the horseradish peroxide days. can also use viruses on a retrograde
22:58 a herpes virus. Rabies virus of greatly traveled from the external terminals around
23:03 periphery into the south, and you use these viruses tagged with some diarrhea
23:09 for strategy peroxide listo. So what saw this periphery or the skin is
23:15 to, what, euros or what of the network in the brain is
23:18 to a right. Dunn drives and explains, recall. This is where
23:24 happens. This is the most Let's reactive parts of the off the
23:30 and this is the second disorder that talked about. This falls under autism
23:35 disorders in particular. Fragile X. are called fragile X so abnormal dendritic
23:44 anatomy formation density can, uh can in mental retardation and it is
23:56 It is a model for fragile X , which is a part of the
24:00 spectrum disorders which were just discussing the in this case, on the
24:05 we discussed that neuron has to intake these that expires. Thousands of
24:10 excited during into their in person, that information sanitary inputs from women with
24:17 tragic receptors from X sanitariums announced mandatory from Gabba Gabba urging south Gabba receptors
24:24 they get their synapses from yourself. again, this is just a repeat
24:30 that. We discussed it for functional that could be different, but in
24:35 sense you still have the input they , uh, region the component input
24:42 , the integrated conduct out and the component beat on the muscle on the
24:46 in your honor in some instances. the calcula right on bond Then we
24:52 , Well, how do you classify these? The firm sells sometimes.
24:55 they said the brain has maybe about 50 different cells are fast. One
25:00 in doing that is through that. we'll follow your anatomy of the
25:05 You polar solve. This is my , Sumida polar saw This is our
25:09 over game And so this is one the neuron sound that listen to grow
25:13 in the spinal cord and this is parameter will sell excited, very
25:19 Cameras that we discussed this widely are for kitchens and officer about have 100
25:25 synopsis still has to very quickly with milliseconds integrated somewhat calculate that information and
25:32 Selma to produce actual potential. Some the gun rights, their spine and
25:38 are spiny. And of course, not enough just to know morphology of
25:42 south. You have to know the at the descent of these local cells
25:47 stay within a local service or whether projection sells most of the protection.
25:51 so excited. Torrey Cells overwhelming majority local into narrows our military cells excited
25:57 investors inhibitory. Whether there has south markers with neurotransmitters to gather when they
26:03 gather, they can also releasing our . One cell can release a couple
26:08 things and constrained from many, many specific markers started inside the specific
26:14 And, of course, the firing or the signatures of actual potentials Take
26:20 , the replaces with this complexity replaces . The context has been input campell
26:25 where we said that have been in . You have over 21 different subtypes
26:29 inhibitory cells in a flanking and controlling activity of these long projection excited terry
26:36 that are not very diverse in And it is controlling their activity about
26:41 synopsis on being strong control over the properties and their distinguished based on their
26:48 . Thes different inhibitor and excited ourselves distinguish one from another based on their
26:54 , based on the actual potential firing and the intracellular markers that we crossed
27:02 while we're doing these specific cellular so we talked about. The cells
27:08 their own dialect, speaking the producing there were patterns of action potentials
27:14 these sorts of physiological importance. Then send it glia, which is
27:19 There is a very important to talk , um, in the periphery.
27:23 have Schwann cells to produce one segment Axiron violent segment of an accent and
27:31 , or have a legal tender sighs you have one segment of the
27:34 It's produced by one process. Outgrowth that a little underside. And then
27:40 talked about how if you have milon , you can have two conditions to
27:48 multiple sclerosis. So keep writing that under. You are, um,
27:54 neurodegenerative disorders list. Also, shark married to disease, So the point
28:01 is that if you have ah, multiple sclerosis, which is a sugar
28:07 model year as a mutation from a tenia me talk too bad.
28:12 You have deem island nation and you this sugar and, like you can
28:16 of tremors like that's almost actually, , trying thio model multiple sclerosis because
28:25 is one of the symptoms of the technologies Team, Island nation and multiple
28:32 . We also way know about all new disorder. Very important about multiple
28:39 . Okay, well, as Promus had tremors and the even can have
28:46 because improper signal flow is in The muscle contraction properly causing these
28:53 And it's not just in the of course, is also the denial
28:56 nation CNN s we're talking about, just the CNS sending the signals into
29:01 spinal cord So you can rebuild this by injecting a transfer. Acting this
29:09 , this animal model normal team. there's potential there were addressing in gene
29:15 how you could repair one that al and potentially repair the casino type
29:20 you know, trying very juices peripheral much BNP 22. We talked about
29:27 features of impaired gait, uh, deformity. So we talked about how
29:32 can combat that with racism diagnosed early . Now we kind of put it
29:39 together. We watched a movie about glial cells that Russian during the injury
29:44 start cleaning up the debris in the dynamic units of the brain. Smaller
29:49 , not only with the process I've movement of so much through the tissue
29:54 . And, uh, we have Astra side. We're gonna have decided
30:01 Myelin Nation and ostracized. That was important for us because our society is
30:05 care of the synapses exercise, siphoning , uh, defusing increases local increases
30:14 a potassium concentration of calcium concentration it and feet forming blood. Brain barrier
30:21 the last checkpoint where things to enter the interstitial space and the space when
30:27 are no networks and the surrounding fluid separated by dependable cells forming a layer
30:36 him directly from super spinal fluid and banana Panama cells with discusses being
30:42 um, stem cells developing into other cells war into neurons and another s
30:52 . That is not showing this And we worked really cool movies about
30:55 radial glial cells. We said that glial cells, so it's not only
30:59 as a latticed when you're also travels their final destinations would also could and
31:06 be in a precursor cells stem cells blue Republican precursor cells to other green
31:13 neuronal. Sometimes and then we finished about blood brain barrier, and we
31:20 the blood brain barrier not only within context off anatomy and how Astra doing
31:26 play very important role in controlling, , blood brain, uh, went
31:32 from the blood into the brain. important player, this barrier, but
31:37 how this plays into the euro, Development. We also discussed the fact
31:46 if you don't have an effect of that is in the form of a
31:50 or another delivery format, that you need to consume a lot of drug
31:58 get enough of it is through across blood brain barrier. And therefore you
32:01 be very cognizant of all the potential effects that a systemic side effects on
32:07 brain regulated side effects. So this all important if you're thinking about pharmacology
32:12 or pharmacology, different treatments, trying, development and such.
32:20 so I'm gonna take a pause and I'm gonna see if there is
32:26 questions on the section on neurons and . Okay, so let me know
32:40 you have any. Uh, if have any questions, I'm gonna check
32:49 hm the chat. Should we know specific days for the exam like the
33:12 date off our off Hippocrates? And I think that it's a good
33:21 It's not gonna be that specific. more conceptual so that you understand,
33:26 example, that Egyptians, although they really sophisticated, what they were already
33:31 with, uh, dissections and ball and things like that they were discarding
33:37 brain is the main organ. That continues so that you should know that
33:41 know that debate starts changing in ancient . So those kind of things,
33:47 not not the dates. I you should realize that you didn't have
33:51 microscopy when you had brain trapper you know, prehistoric times. And
33:56 know, so you have and a general timeline and key events that happened
34:03 us thio what we now call We're going through some research in regards
34:10 the phenomenal receptors the peace receptors inquire , a similar chemical to potentially in
34:17 receptors for CBD to bind. But is the case, and that means
34:21 CBD does not offer any benefit without president's or THC. Any similar compound
34:26 undermined. Okay, so I don't I'm gonna answer this question because it's
34:32 related to the material for the not not to confuse all of the
34:38 on this review or that may be at the review. It's a great
34:43 . It's a great question that relates in the cannabinoid system and interaction of
34:49 cannabinoid system with phyto cannabinoids that are that are. We have endo cannabinoids
34:55 our bodies, and we have phyto in nature. And so what are
34:59 interactions of these nature molecules with our and without under cannabinoid system? We
35:05 a lecture coming up toward the end the exam that I will discuss under
35:11 . This is very interesting for So hold off. Or maybe,
35:15 , email me privately if it's something really interesting and requires attention. Urgency
35:25 a bipolar neuron is a conductive region split into two regions. Bye whole
35:34 has, uh, Axiron and then . If you're talking about pseudo unit
35:43 , then you have to regions the Axiron it conducts, and this from
35:52 periphery. They're both af Aaron's, actual dorsal root ganglion. Selma's are
36:00 outside the spinal cord, and then central acts on will take from this
36:08 outside the spinal cord into the spinal information through the central accent. So
36:14 think you could view that the pseudo poll ourselves has this conduct. I'll
36:21 split in two. Um and so sorrow about the checkpoint in the
36:28 if you may think of it off signal that travels a fair and signal
36:33 goes from the periphery from the muscle the, uh, spinal cord you
36:39 toe label would have to put So you what's wrong with her?
36:47 I think I'm not very clear about question, but I hope that I've
36:52 it already. Could you please explain use of Caliban Din? Um,
36:59 not for our purposes. We don't need thio. No how we use
37:04 indent. It's these thes air, air calcium binding proteins. These are
37:12 of the molecules that could be specific the cells. Like we discussed
37:16 Brendan or Samata Statham provide human. , the take home message is that
37:24 don't have to know these chemicals were really focusing on them, but the
37:29 that these different subtypes of cells, they're excited terry cells, they may
37:34 a distinguishing internal factor that the marker cellular marker or whether they're the inhibitory
37:43 that is so diverse and have different on top of this different anatomy that
37:49 need to cross stain in order to if you're let's say you're an electro
37:56 and you have this view off cells you suspect that you are in a
38:01 layer and you patch yourself. But you want to really say that this
38:06 that number seven out of 21 So to do that you have tow
38:12 anatomy on the location of the You have to know the firing property
38:17 that So the physiology of that how it reacts to stimulant. Then
38:24 have thio understand the intracellular markers that found inside the cell because cells can
38:31 similar and fire similarly. And the distinguishing factor would be that well,
38:39 of them have these calcium or uh, proteins of interest inside or
38:48 or neuro peptides that they release something is unique to them that will actually
38:54 that. That would be the third factor. So these are all good
39:02 , all right, I think that gonna pause the recording and forward,
39:06 , that last morning play this part you. So particular theory thought that
39:26 , when in early days Nure Anonymous scientist started addressing while What is this
39:34 ? What one structures? That many , many connected structures. When you
39:40 out the brain, it seems to all interconnected because there was no
39:45 You really couldn't see individual cells? . A lot of scientists took the
39:52 that, well, you know what brain is is one continuous sensation with
39:59 stands for like a network of living . But instead of being individual wrapped
40:08 in some numbering and communicating to each through synapses, they said, you
40:13 what? It's just one continuous side Plas Mick entity with millions of nuclear
40:22 . So he didn't think that the on the neurons in the brain where
40:27 we're discreet units that they were not physically thio other units. They thought
40:33 they were all physically connected through this member. One plasma member, one
40:39 surrounding this really, really complex structure the brain in the spinal cord.
40:44 that's particular theory. The neuron doctrine is happening at the same time when
40:51 , previous classes, you may have the cell theory neuron doctrine and or
40:58 South theory. In case of doctrine is relevant to the nervous system
41:03 each one of the neurons, each of these cells, such a see
41:07 one of these black cells is separate all of them. And I think
41:11 act to each other through very, special areas that we call synopsis physically
41:17 actually not connected to each other. do not touch each other. There's
41:23 nanometers of space between the synapses between cells. Okay, so this is
41:29 neuron doctrine, which is in opposition ridiculous theory and other interesting fact.
41:38 career Sort of a lesson fact was familiar Golgi, who invented the Golgi
41:46 , believe in particular theory? Monica Hall, his student gorgeous student
41:55 this Golgi stain and making these He was a huge proponent of neuron
42:01 , and then both of them accepted prize together. So does that answer
42:06 question? Yes, it does. you. Great. Any more questions
42:12 this on this section and neurons and when you just strike chat real quick
42:33 sorry. Uh, so I think gonna pause for a second and forward
42:56 . Let's talk about that. So we moved into a new section I'm
43:02 move into the new section is I'm your question here. Very good
43:07 So we talked about all of this . We talked about how there is
43:11 separation of charge across plasma membrane. then we talked about how these amino
43:18 have built into programs, and these are channels, and these channels are
43:25 for certain ions are recall some of things we talked about on selectivity,
43:31 we talked about the fact that there's ingredients and concentration radiant in electrical radiant
43:37 thes science across plasma membrane, either outside to enter inside out. And
43:42 we have the a t p ace , which uses a teepee and energy
43:47 order to transformed in just one direction against concentration, radiant of these
43:58 So for each two ions, it potassium ions, transports inside the south
44:06 three psyllium islands out to these problems . Then, before we delve into
44:14 of the physics and physics representation of plasma member and Another thing is we
44:19 toe. We call that we talked the circuit. So please review the
44:25 and the reflex arch, um that discussed. Know what the stuff
44:34 morphological subtypes that are censoring neuron inhibitory the motor neuron. What types of
44:42 their release. And to recall these services three cells that are involved there
44:50 still read ganglion cell and the inventor of the spinal cord and the
44:55 We know that they all have different of morphological in different polarities and that
45:03 also excited or any of it very the circuit. Well, then we
45:08 on to talk about Ionic movement across , Remember? And then we said
45:13 there is actually to force is it's just a chemical radium, but it
45:19 also the electrical force, or electro force that now builds across plasma membrane
45:25 establishes what we call the Librium potential ion such as potassium. He also
45:32 that charge separation is across plasma and so if you look into into
45:37 side of salt inside the neuron or extra cellular space, further away from
45:42 membrane is charge neutrality there's equal amount positive and negative charges of accumulation of
45:48 negative charge on the inside of the and positive charge on the outside of
45:54 number. Earnings is just across the membrane. And so we introduced this
45:59 of the driving force here also, you said, then reviewed to stand
46:04 me for sodium that would depend on chemical of electrical forces. And then
46:11 said, It's these air. The important species of violence had set up
46:16 resting member of control, and we that they have different Miller molar concentrations
46:22 the outside of the cell versus the of the cell, which can also
46:27 represented by ratio. The ions outside inside of himself and then each one
46:33 these ions sodium, potassium chloride and have their own equilibrium potentials or their
46:39 reversal potential. So when we talk reversal, put ourselves now, when
46:45 talking about is calculation for each individual using Marist equation, you will not
46:53 a calculator for the task. This one answer thio. One part of
46:57 questions you will not need to calculate of this test, but you will
47:01 toe. Recognize. For example, council does this formula. Abbreviation 30.77
47:08 Boleslav. Calcium outside versus calcium inside correct, and I may ask you
47:14 question, Brian. Starting a different main sort of value of 61
47:19 And if you don't know nursed equation one of the variables a surveillance to
47:26 , then you would not know the that he calcium two plus would have
47:33 Uh, if you plugged in. you see a formula that says the
47:38 of the potassium outside is 10 times , I'm sorry outside is 10 times
47:44 than on the inside. Then you'll something is wrong with it. There's
47:48 potassium ill inside, so this is wrong representation of the formula. That's
47:52 knowledge and understanding off the formula, not the actual calculation. Nurse equation
47:59 allow us to calculate individual equilibrium Golden equation will, uh, use
48:06 introduced the permeability term. The membrane mostly permissible to potassium addressed 40 times
48:12 permissible than it is to sodium and now, permeability and concentrations,
48:19 for both islands, potassium and and you can even add chloride onto
48:25 list and therefore the abilities. Now can calculate the overall number and
48:30 which is P m. So I hear you have e k e k
48:35 a a c l individual ionic liberal and PM is the some of the
48:41 , most formidable almost, uh, ion. So you can see that
48:46 of potential pretty much could be just by calculating all the concentrations of the
48:51 is for potassium and sodium. s. So this is the nurse
48:58 . This is now the Goldman And then we moved on to talk
49:03 spatial buffering how If you increase extra protection concentration, you will d polarize
49:08 plasma members. So if you could it beyond 10 million Mueller so normal
49:13 is 3.5 about $5 million fee 10 or 12 million. Mueller,
49:18 actually reaching the threshold for actual potential . So we talked about how
49:24 uh, Leo cells will be responsible spatial buffering for absorbing these high concentrations
49:31 potassium and offering goods interconnected processes within and between exercise through that specific network
49:40 these local rises and concentration being potassium calcium or human neurotransmitters in some
49:46 Then we talked about that their channel okay, and that these channel dynamics
49:53 they have a particular structure talked Shakur flies a mutation that made flies
50:01 gene mutation that using these mutations that toxins using electrophysiology. But McKinnon was
50:09 to derive the structure of the cultivated potassium channel. It's important we talked
50:15 the conserved amino acids, and then talked about the fact that he also
50:20 the or loop inside the channel, starts us essentially a sieve, molecular
50:28 or islands coming in leaving through that , and that the conservative, you
50:34 , assets could Then, by studying flies like food flies, shaker flies
50:40 be gained. They have Kamala Ji the structure of the protein, and
50:45 determine it's an important part of this and the flying. And that might
50:50 out to be a very important part the human, which could then be
50:53 for subsequent drug development as well. we started talking about actual potential,
51:00 your question was about the Your question about number of equivalent service and the
51:07 home message here is that again you not need to calculate circuit. There's
51:12 here that you're calculating, but you to realize that you have very important
51:16 that you have the term off driving , which is the difference between member
51:20 potential in the Librium potential so that equals IR can be rewritten. Driving
51:27 equals I R. And that driving VM here I equals v times G
51:35 this case, the conductors, because equal one over r. So you
51:40 that your total current will depend on conduct mints and the driving force in
51:45 conductor's three individual channels and overall The number of all of the channels
51:50 individual channel. Then we said in one of these channels and peace of
51:55 membrane could be represented with equivalent circuit circuit. Each one of these will
52:02 their own membrane resistor conductor, and also have of diary electro motive
52:12 And so this this this started Somebody had a question. What is
52:18 flux? This is just passive circuit the right here on the top.
52:21 doesn't show any flux. And if is any flocks that is probably not
52:26 dominating in any direction. And then is no net flux in the passive
52:32 on Not necessarily yeah, uh, comparing it to the bottom, which
52:40 really an active circuit. And now can see the conduct insists of sodium
52:45 from outside to the inside production from inside to the outside, the pumps
52:49 against Constitution. Immediate, very important . We talked about the properties of
52:56 capacitors having good capacitor having large membrane opposed to resistor, that the membranes
53:02 R C circuits, their combination of and capacitors. There's a resistance into
53:08 south that resistance, the bigger the , the smaller the resistance, but
53:12 capacities to bigger the cell that higher capacitance. Nothing you have was charged
53:18 , which states sometime. And we the ivy properties or the electrical
53:25 Electrical curves for the membrane overall of individual channels that we discussed later In
53:31 course, you will not need to a calculation here, but you will
53:35 to recognize what is flowing where I'll doing because the action for control you
53:42 have this type of circuit Onda or will say, you know, a
53:47 type of question. But now the message here is that the permeability ratio
53:54 . And if we have a huge for potassium, addressing number of potential
53:58 the action, potential department ability is highest Soviet. So when we talk
54:05 action potential, we had thio review well which clams circuit and the take
54:09 message here is that voltage clamp allows to clam the potential to hold the
54:16 . It allows you thio, isolate and different holding potentials and using the
54:22 clamp and setting that number of potential levels So you can highline different currents
54:27 interests. And now you contest where ions actually exhibit their reversal. So
54:32 calculated and now experimentally you confess me voltage clamp here and you can see
54:38 52 million balls, which is the potential for sodium you, don't you
54:43 longer seeing inward current, but instead current now becomes a little tiny blip
54:48 awkward current sodium is now, instead flowing into the south, Sloan from
54:53 the south out of the celebrated And as you can see, the
54:59 of these currents during action potential. such that inward current this early is
55:04 , but it's transient and as deep to sustain the outward current. Which
55:10 current is late activating, but it sustained throughout the people authorization. So
55:15 discussed that this deep polarization during the phase of action potential sodium influxes of
55:22 of sodium channels, opening up and reflexes is somewhat individual potassium channels opening
55:29 . We distinguish between the dynamics of channels being very different. Then we
55:33 last couple of lectures we home been on the sodium channel, so I'm
55:38 going to go over that much over . But we talked about all the
55:42 , sodium channel, both educated, love to get in costume channel,
55:48 voltage gated sodium channel, we said a sensor. And as for the
55:52 loop, it's important, and later also talked about segment that's safe,
55:57 is important for light okay and Now we talked about sodium channel kinetics
56:03 it has to gains, so I'll this really quickly when you get deep
56:09 . Sodium channel activation gates are now up number two that sodium Channel
56:16 and that is because the voter sensor up this channel and changing the confirmation
56:21 the whole protein. But as it the confirmation that opens activation gave us
56:26 in chain represents inactivation the activation swings closes the channel as it closes,
56:33 General Court will stay there until the of potential gets hyper polarized to at
56:38 the threshold for the action potential ATTN. That point, there will
56:42 Dean activation. The inactivation did released the activation gave them clothes, and
56:49 sensor will reposition itself back in this position. Now the number four the
56:54 again is ready to be stimulated with polarization and go to number one.
56:58 two open and transient. We opened channel gap, so we discuss this
57:04 it relates to the absolute relative refractory . Also, um, and we
57:14 discussed the different modes of recording patch reporting using voltage clamp recording, which
57:20 allow us to test the conduct. how well I answer conducted through these
57:26 like sodium channels, and we have types cell attached inside, out and
57:30 out. Reporting number inside out will cytoplasmic domains to the outside world.
57:36 world experimental conditions outside. I will the excel in the domain of that
57:42 to the experimental on conditions. And we moved on to talk about toxins
57:47 say, Look, we have all plans, but toxins and the toxins
57:51 important because they block certain things and discuss these toxins and enough details.
57:57 need to ask you questions about ttx Saxon toxin light. Okay, and
58:03 is additional material that is posted on . But we if you review the
58:09 from last two lectures, you You will recall all of the information
58:17 is necessary for you to know, I don't have to repeat myself,
58:21 they get to your questions. But to use these blockers tt access specific
58:25 sodium obligated sodium channels until she was and his article that is posted for
58:32 guys talks about how tetrodotoxin block the . Gated sodium channels were blocked that
58:38 potentials altogether. But if he needed voltage clam, he needed a combination
58:43 the voltage clan and tetrodotoxin in order isolate the cars, blocked the cards
58:48 show that the tetrodotoxin has no effect multiple gated potassium channel because it has
58:53 effect on these outwards. Investments has in blue, as opposed to tetra
58:58 ammonium shown here on the right, belongs potassium channels and does not affect
59:03 n word sodium for so inward sodium is there doesn't affect sodium channels have
59:09 the passion channels, and you don't this awkward cast. So you had
59:14 . Question. How this cocaine interact sodium channel that may show up is
59:21 test question. And then we reviewed V curves, and we talked about
59:26 if you open the channel, some the channels are linear. They have
59:30 I'd currents, which means that for same change in the current or the
59:36 change in the voltage current is dependent voltages on the current in the linear
59:42 . Same amount of people ization or an opening of a current at certain
59:47 level on. This is how you start diving plots or our current voltage
59:55 . And we talked about how a of these flaws air, actually rectifying
60:00 they're non linear. Uh, they're linear. And then the last talks
60:06 that we discussed was lighter. Game review will be discussed about lighter
60:10 and that's the most common local and on aesthetic. But there's an important
60:18 about lighter game that you should based on the fact that it has
60:22 binding side on the inside of the of plastic side of. This was
60:27 in the sodium channel party. So you're setting single channels, that's
60:34 Sometimes it's hard to distinguish activity of channel. So you want to go
60:38 systems where they will allow you to over expressing channels, determine the exact
60:42 and go back into more complex Using now, mathematical calculations and a
60:48 of data actually find the channels of and more complex systems. And,
60:56 , now we before we talk about off action potential as you recall,
61:06 so um influx. Potassium. The . Driving forces and delivering potential stroll
61:12 member and potential resting member and potential action potential threshold value. A positive
61:20 loop for sodium, demobilization, sodium Study. Why doesn't reach the liberal
61:25 for sodium mhm because driving force decrease ? Because the inactivation gave closes on
61:31 driving force of potassium increases have huge of potassium going outside. Meeting the
61:37 outside when you have the reconstruction rebuilding this charge, separation across parts number
61:43 the slow, much slower fashioned by potassium. So when the channel sodium
61:48 opening their inactivated there, there's absolutely period where you cannot Yeah, they're
61:54 another action potential because they're pulling So the internal supplying that there's no
61:58 polarization. So you have the hyper pies, my number it needs to
62:02 actual potential threshold of the law. then there's Blue Zone is relative
62:07 Period zone is where you can Now. There is enough of being
62:11 that channels that have been deemed activated close. So if there's a stimulus
62:16 in during the relative refractory period that member of Potentials cell will be able
62:21 do some other actions, then I like to share with you yet about
62:32 scream from this is our Ivy If you remember, I said,
62:39 if I place a TV plot and said that it crossed zero land?
62:43 zero current amount of savings, said would represent potassium potassium was going,
62:51 , awkwardly. Potassium is leaking from south into the outside, and we
62:57 , Civilian is going inwardly is an cards until it reaches positive 55
63:04 So, of course I did all these, uh, drawings here,
63:12 you can make your own drawings. was just thinking of posting this home
63:18 they're like abstract art with something like would be interesting. Linear versus rectifying
63:25 of by the saving original Positive You should be able to identify the
63:30 or sodium with this linear channels for it's so this is something to review
63:40 . What is the difference between when in rectifying again? The rectifying?
63:48 see this linear on the left So it's a it's just a straight
63:52 . Linear means that for the same of voltage that you change like this
63:58 you will have the equivalent amount of change. But in rectifying if you
64:04 , let's say here you have inward . You can see that if you
64:10 this this blue line, do you the same amount off current people.
64:17 so if you have this current negative . Here you have low conductors.
64:22 were conducted so it is low. if you go to positive one,
64:27 a pair or hundreds become pairs of one that have currently the same equivalent
64:33 for the negative. But you inject same amount of positive card. Now
64:36 can see that you remember and potential has changed tremendously. Or you can
64:42 that away for the same change in number of potential value. You see
64:47 Go away from zero value to the or to the left and see where
64:52 , where you have more conductors, have more and changing the voltage just
64:58 you This is ratifying, which is preferring to conduct ions in a certain
65:03 in this case outwardly. Does that your question? Yes, it
65:09 Thank you. Uh huh. yeah, can you go back?
65:16 you said that this was outward conducted it shakes outwardly. That's the second
65:26 picture on That's life. Yeah. . Uh, let me actually not
65:36 if I heard your question correctly, should go by this guy from
65:41 And so when I said outward current , you know that outward current will
65:46 different for the different ion, depending the delivery of potential. So he
65:51 the inward current. In this it's just bottom deflection Here on the
65:56 current was the top reflection. So I said outwardly rectifying yes, its's
66:03 Thio rectifying the outward direction like in blue line here. And how would
66:08 tell something was inwardly recertifying. You do the measurement of that curve and
66:15 may end up measuring something that would like this. Oh, okay.
66:24 so that's that. That's the point that membranes and cells will have ah
66:30 of these channels with these different some of them an orderly, some
66:34 them awkwardly rectifying, reversing a different . You know, some of them
66:40 it overlapping potentials. And that's why had that crazy diagram with all these
66:45 because really, the so we have compute from about anywhere between 10 or
66:52 of these different curves coming from different . In order, Thio give a
66:56 response and the blast, my mom good questions. So I'm gonna go
67:04 to see if we have a few of the material to go through.
67:10 is a vibe rectification. I think is maybe the main slide, and
67:16 encourage you to look at that article that I've posted. But I hope
67:21 this was not too confusing for but But we do have this back
67:26 spikes that we're trying to solve. do we get the backwash of this
67:30 something? And what does it Those back propagating actually Formula pause here
67:35 a second. I wanted Thio. if, uh, you have any
67:44 questions? Uh, that for the now that we were covering do accents
67:54 any points have spike like projections Or always a single nerve, uh,
68:04 by for Kate. So they I think that what is Maybe what
68:08 trying to get that with this question that accidents can buy for Kate.
68:13 they form different arms, uh, can have multiple synapses stand on each
68:20 and member in circuits is that I'm force Sammons electro motive. Ah,
68:29 , yes. It is the electro force because you are essentially taking the
68:34 between what was based on both electrical concentration, radiant and uh, that
68:46 is It's electro motive for force of chemical electrical motor force. Can you
68:51 over the noticed equation again? It's the video. It's in the original
68:58 for nonce equation, so I think the best way for everybody to use
69:02 time if you go back to the video, I spent quite enough of
69:06 on that. Please reviewed in the face pathway in the dorsal root ganglion
69:13 cell affair himself. Um, dorsal ganglion cell is an affair in cell
69:20 carrying the signal to the spinal Can you go by the atomic linear
69:25 or name King? Yeah, so think that if you re watch the
69:29 five minutes, it's ah, it answer your question. We can listen
69:38 the rest of the video on our . Yes, absolutely. And there's
69:42 about 10 15 minutes off the video just to clarify my question. Why
69:48 current accesses? Voltage correct? Current positive outward. If it's negative,
69:55 inward. Yes, it is. is by kind of a definition on
70:01 . It's difficult to explain why this the convention. There is only eight
70:08 of blood. Those the only lectures on the exam. Yes, it's
70:13 We had eight lectures and a And so those are all eight lectures
70:18 be covered on the exam. I that maybe we're going over time a
70:22 bit. An important message here is want to tell you before,
70:29 play and review. The rest of material is that I'm wishing you lock
70:34 Tuesday toe review all of the material material, video material. If you
70:39 any issues on Tuesday, Police contact immediately. If you have any support
70:44 testing issues, I will be on online and checking my emails regularly.
70:50 you don't get any answers from if you call them or email
70:54 you can email me and then hopefully can try to solve whatever issues you
70:58 have with log in, or trackers whatever. While taking the test
71:04 Use the sample exams that are on blackboard. Thio, test yourself.
71:12 I'm gonna now play the rest off material that you should be,
71:19 knowing for this exam. And this the formation of action potential. How
71:24 actual potential get produced attacks on initial and how back pocket. So we
71:29 about to some types of sodium channels maybe 1.2 which high threshold requires a
71:34 of positive current in order Thio for water sensor to shift and open up
71:41 channel, maybe the main slide. I encourage you to look at that
71:47 again that I've posted. But I that this was not too confusing for
71:52 , but But we do have this propagating spike. So we're trying to
71:57 How do we get the back It was kind of something. And
72:00 does it mean was back propagating, , So we talked about to some
72:05 of sodium channels, and maybe which is a high threshold, requires
72:09 lot of positive current in order Thio that Walter sensor to shift and open
72:16 the channel. And so if you incoming deep polarization that may overcome inhibitory
72:22 , passes through the cell are Remember, it's very specialized place
72:27 On initial statement, I saw the offices where the actual potential is going
72:32 be produced, bypasses the zone of receptors, which are located closer to
72:38 summer. Because the current by itself not strong enough. Thio open up
72:43 channels that they're suffers but these multiplication channels. But when it enters this
72:48 zone, which is a little further from the SoMa, that yellow zone
72:52 inhabited with low threshold and 81.6 which require little current in order for
73:00 voltage sensor to slide and has sensitive to open up the channels generated actual
73:06 list explosion. Basham Some potential will forward and to drama or forward.
73:15 sorry, Orson Drama were forward propagating potential, and then you will have
73:22 for these n 81 point to the polarization is still coming in is actually
73:28 is being generated. Now you have summation of these positively polarizing snap again
73:34 positive current that is generated from the potential. Some of these positive inputs
73:39 this zone with the Pro Bowl starts up high threshold channels now XYZ high
73:46 because there's this positive current from synapse positive come from the actual potential in
73:52 Yellow zone and opens up in 81.2 , um, generates back propagating actual
73:59 . So we talked about how bad action potential it is very important
74:06 uh, synaptic plasticity and important timing dependent plasticity. And we talked
74:12 how the longer time period of days the South for other self to stimulate
74:18 sound from the South to respond to lists relevancy that cell has because in
74:24 brain things have to happen on No seconds, few milliseconds. So
74:29 you have inputs being activated and the and was being activated, cell doesn't
74:36 within a few milliseconds. Send these are feeling with meaningless. They're talking
74:42 somebody that doesn't respond to them. this back propagating Spike informs the rest
74:46 the seller participates in what we call dining in the city. And it
74:50 the timing to clean the inputs coming the synoptic inputs and the spike just
74:57 here. Despite refers to the actual that gets produced the backs of initial
75:02 despite coming dependent plasticity of this back spike. If you block the back
75:08 spike, just producing forward propagating you cannot have these synapses and didn't
75:15 this plastic or you cannot have them at all. The publicity changes.
75:24 if you respond within a few milliseconds auditory signal. You strengthen this
75:32 but if that time period shifts to of those seconds to hundreds of those
75:38 , you actually depressed the synapses. depressed the signally saying it's irrelevant.
75:43 busy and fast processing something else, ? He's a kind of some of
75:48 learning rules, I guess, and substrates of these learning and memory in
75:56 , uh, in our branch. I think we This was probably the
76:02 slide. Maybe there was another slide said, Why should I care about
76:06 action potentials? Give you a home question or problem? Uh, pressure
76:12 about which direction to turn bright Appointed you to a couple of articles
76:19 online for you. The white Okay, so bring on your
76:29 Okay? So let me know if is anymore questions. Let me know
76:39 you have any questions. You can email me if it's something that doesn't
76:48 answered. If you have simple the best way again, if you
76:53 take good notes on it is to to video points video points that I
76:59 have mentioned this to your class. mentioning it two or three times,
77:05 , some students having difficult time logging there. You know, I do
77:11 Thio sometimes close and reopen the It does give me a warning that
77:17 taking me to on safe side. still proceed on my computer because I
77:23 I'm going to video points. I know if I'm getting that warning,
77:28 sometimes the switching a browse or sometimes shutting down the computer and restarting it
77:35 that's what it takes for me to the video. It's not perfect,
77:39 once you get there and if you , I think it's it's really
77:43 it's it's very user friendly. You go back and forth, wife,
77:50 over the slides and material and review . So I think that that's probably
77:55 best way Thio prepare for the If you have any questions now,
77:59 that still doesn't answer your questions and free to email me hopefully tomorrow rather
78:05 over the weekend. Other than that you good luck studying for the exam
78:11 preparing this weekend and taking it in on Tuesday. Thank you for being
78:17 . Have a good weekend productive weekend I will talk to you next
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