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BIOL 4315 Neuroscience Tue Th 8.30-10am - NEURO Lecture 02 History of Neuroscience Tue Th
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00:02 Welcome back. This is neuroscience lecture . It's a cold, rainy and
00:09 morning and I am glad that today to the weather, we're actually doing
00:18 remotely on zoom. Um of course hope that everyone has found themselves a
00:26 spot whether you are the university, the library and the lab and the
00:33 shop or at home and I hope stays warm. We learned some lessons
00:39 texas here from last year in the . In any case, we'll continue
00:45 and discussing the history of neuroscience today we discussed quite a few things I
00:52 you this image and asked you to about neurons and these networks of neurons
00:59 are interconnected that make larger structures like nuclei. They've comprised the lobes,
01:05 hemispheres of the brain, the brain and the spinal board which are all
01:11 parts of the central nervous system. stopped along this historical timeline and a
01:21 locations and really once around the world we talked about different aspects of the
01:29 and the foundation of neuroscience and we about the brain trepidations and postulated that
01:35 potentially were the first neurosurgeons and neuroscientists we're using brain tripper nations for conditions
01:45 hemorrhaging or bleeding in the brain or cerebrospinal fluid formations where you have to
01:52 a window into the brain and that has to be gained through the
01:57 So you have to make an opening the skull in order to gain that
02:01 into the brain and deal with traumatic injuries and deal with other conditions.
02:08 in Egypt, we discussed Imhotep who extremely smart at the time and had
02:16 up with different descriptions of head traumas different descriptions of anatomy and even recognizing
02:25 functions of the brain, meaning that the brain is injured. Then on
02:31 one side, like on the you may lose a feeling or ability
02:35 move your right hand, and Imhotep that he has these beautiful hieroglyphs about
02:40 brain, about the convolutions that are on the surface of the brain,
02:45 membranes almost like an umbrella that covered brain. And you'll learn later these
02:50 the meninges that covers the brain surface also membranes that cover individual neurons and
02:58 as well as cerebrospinal fluid here, a fluid pouring out of the bucket
03:02 he describes invades the brain. In Greece, Hippocrates is proclaiming that the
03:12 is actually the most important organ of body. Egyptians don't believe that.
03:17 even in Greece, this debate is . There's a major shift from
03:21 Egyptians already recognized the brain is the of intelligence, but even in in
03:27 , the Greeks recognized it as a of intelligence. The brain but Aristotle
03:33 still thinking that heart is the center the and I was described to you
03:41 lecture up until renaissance times, it's really not allowed to dissect human bodies
03:48 human brains. And so then the of the human anatomy is based on
03:55 the glimpses of these windows following the to human bodies allowed scientists and doctors
04:03 look into meaning that you cannot do and surgeries. You cannot just open
04:10 study human body even after death. not allowed to do that until renaissance
04:17 . So the human anatomy and brain and general body anatomy up until renaissance
04:25 is dominated by this fusion of what been observed during traumas and injuries such
04:33 in ancient Egypt by Imhotep and later the roman empire during gladiator times by
04:41 unanimous called gallon. So these windows injuries and again it's difficult to look
04:47 the brain and see its anatomy without dissecting it. And gallen also used
04:53 of these descriptions based on paintings. only in the renaissance times we were
04:59 to look into the windows in the and address the soliah's picture here.
05:04 studies anatomy and describes detailed human anatomy the body and the brain and when
05:11 opens the brain, he sees these ventricles that are sitting inside the brain
05:16 these electricals are filled with fluid. this ventricular localization of brain function is
05:23 is dominating the thinking that there's something these fluids that get transported out of
05:28 ventricle from the brain that controls the and many other functions. So we
05:35 start recognizing the salary is that there gray matter and there's white matter.
05:40 gray matter is spongy and software and matter is harder. Gray matter turns
05:45 to be the so most of neurons white matter are the projections of the
05:50 ated axonal interconnections in here in the and then between the cortical hemispheres as
05:58 . So he postulates a green matter it's spongy, it's a place where
06:02 learning and information comes in explains memories formed and white matter potentially somehow communicates
06:09 information to. However, it is dominated by ventricular, the central point
06:16 view in this case rene de carton origins of mind, body distinction.
06:21 so comes up with interpretation for you connect with the spirit that spirit somehow
06:29 visualized through the eyes. That information into pineal gland. And then he
06:35 human body as a fluid mechanical So there's some fluid in the brain
06:41 the ventricles. He also was postulating potentially gasses that are formed also.
06:48 so when this contact which is basically conscious perception, thinking, interpretation.
06:56 beliefs, connections with higher powers at , goes through the pineal gland and
07:02 some sort of a fluid flow and flow through the nerves that then result
07:08 movement and speaking as well as He also very clearly distinguishes or a
07:17 card between reflexive behavior and cognitive conscious behavior is minimal if you may comes
07:26 with the phrase I think therefore I readyto go soon Luigi Galvani Bonnie and
07:34 80 in Italy up until now were by the thinking that ventricle still with
07:41 are extremely important and that there is sort of a fluid mechanics model that
07:47 the brain activity and body activity through ventricles. And we recognize that the
07:52 is the seat of insulin, the important organ in the body. Digital
07:59 discovers that nerves are wires, few , the nerve going into frogs myself
08:06 shot his frog's muscle and demonstrates that shocking either the muscle or the nerve
08:13 is projecting into the muscle, it the contraction of the So he proclaims
08:19 nerves are not pipes of channels has a card with his contemporaries previously were
08:27 but there electrical conductors and in addition can generate electricity. So 1780 is
08:35 Luigi Giovanni proposes that maps can generate . Not until the middle of the
08:42 century, we actually have the recording of microelectronics to penetrate individual nerve
08:48 Are these individual wires and pick up electrical activity so long time transpires before
08:55 methods um physiology and bio electricity, he started in 7080, definitively proved
09:04 demonstrate and visualize these very fast electrical created in these wires that we
09:11 And those action potentials paris can generate and just admitting a few more falls
09:20 cns major divisions. We already discussed cerebellum and brainstem spinal cord from the
09:27 cord, you have spinal nerves coming and of course you have the peripheral
09:32 system but the focus major focus here we will not really talk about
09:37 N. S. Much major focus is A C. N.
09:40 Neuronal and glial functions especially in this section. Now we also talked about
09:46 major lobes and these major lobes. lobes are shown here. Yeah you
09:53 the frontal lobe, frontal lobe which separated from the parietal lobe by central
10:00 . It's in the back. You the occipital lobe. Yeah you have
10:06 sylvian fissure which separates the temporal lobe the parietal lobe in the back of
10:13 brain. You have the cerebellum. just the brain stem right here.
10:20 you learn different parts of the brain going down into the spinal cord which
10:25 into your spine. So these types diagrams are very problem to appear as
10:32 . Labeling questions for example and they you can you label a central sulcus
10:39 sylvian fissure or if it's a functional I may ask you this lobe.
10:48 lobe is tasked with that's for example a lobe and the choices will be
10:54 find identifiable logo that is responsible for information processing and you'll have to identify
11:03 occipital lobe. Okay so these are good labeling diagram questions that I have
11:09 the exams. Now we also discussed spinal nerves. Each one of these
11:15 of 31 pairs of spinal nerves is of the sensory fibers that come out
11:21 the skin muscles and joins these axons come out peripheral axons and go into
11:28 dorsal root ganglion from the dorsal side the spinal nerve here and enter into
11:34 dorsal side of the spinal cord carrying information. And all of the motor
11:41 and motor control of the muscles is by the motor neurons that are located
11:48 the ventral side, ventral form of spinal cord. And so the output
11:54 the, so most of the motor located in the spinal cord will be
11:57 axons but also are informing the same bundle. So each nerve consists of
12:04 sensory components and the motor component. motor often referred to motor component by
12:11 axons from the nerve fibers that would in and actually innovate and cause the
12:17 of the muscles. And you'll know whole circuit really well. And you
12:23 also know the major players that involved sensory cells which endorsed the ganglion
12:28 the motor neurons, um as well the interneuron. So they're located in
12:34 spinal cord, As we discussed from century onwards, there is really a
12:43 thrust in trying to understand localization of functions in the brain and what we
12:52 up with this size of chronology led joseph franz gall, which proposes that
12:59 brain is the organ of the The mind is composed of multiple,
13:03 innate faculties. So these organs outlined on the skull because they're distinct.
13:09 faculty must have a separate seat or in the brain. These organs at
13:14 35 outlined on the skull here, the size of an Oregon, other
13:19 being equal is a measure of its , saying that if somebody's brain or
13:24 air in the brain is bigger, then it's a measure of the power
13:29 that specific area of the brain. that specific area is responsible, let's
13:33 , from mathematics and that area is large. That means you're very good
13:37 mathematics in a faculty. So the of the brain is determined by the
13:42 of the various organs as the skull its shape from the brain. The
13:47 of the skull can be read as accurate index of psychological attitude and
13:51 So what made them think that this be actually done? So what made
13:56 think that you can read the book its cover? Well, because they
14:00 , you know what? The skull valuable. So it's soft during early
14:05 shapes around the brain structure. So you have abnormal development in the
14:11 then you may have a distortion in skull and so on. But they
14:14 that it's beyond that if you can at little bombs and symmetries and circumference
14:20 and angles on the brain and actually certainly made faculties and individuals and following
14:26 chronology section session with the criminologist you , you measure your head with different
14:33 , he would tell you that your . So and so here uh scholars
14:39 pronounced bond and it corresponds to certain faculties like generosity, for example,
14:45 very generous person. That's what chronologies and of course they were wrong,
14:51 what they were right and what they really good for in the stage.
14:57 the neuroscience development is trying to compartmentalize brain into different regions and trying to
15:03 see which region of the brain is for what faculty or what function.
15:08 they were wrong is that you cannot that from the surface, so you
15:12 read that by the bumps and angles circumference is and sizes of the skull
15:21 as I explained that if all things equal the size of the organ methods
15:27 . The largest animals with the largest are elephants, that would make them
15:32 smartest animals in the whole world, than humans. So they should be
15:39 , Sitting in lectures are typing something the chat instead of sitting in the
15:46 baths. So this is this is really interesting because there's this ongoing debate
15:53 find different parts of the brain that responsible for different functions. Paul Broca
15:59 up with brains that are very And of course we're talking about 19th
16:05 and he has a patient that has aphasia patient has difficulty in conveying thoughts
16:11 speech or writing. So the patient knows what he wants to say.
16:16 patient hears the words coming in, the words, but the patient he
16:22 she cannot find the words to to but cannot express the pattern of words
16:29 is meaningful. So postmortem after that broker looks and he says,
16:35 there's a hole in this area, of me. And he names this
16:39 Broca's area and he says, well now he's on a quest to
16:45 more brain. So he writes letters all of the physicians and neurosurgeons that
16:52 at the time there, a he was a neuropsychologist, he was
16:57 in speech and he writes to them says, you know, if you
17:01 any brains from your patients or if patients have this type of problem expressing
17:08 and after they die, or if have their brains, please send it
17:13 So you can like the number of . And he observes from the descriptions
17:17 folks that had expressive aphasia to some had damage to this part of the
17:22 , which this part of the brain referred to as Broca s area.
17:27 we also discover later uh over Nicholas veronica discovers this area. If you
17:34 damage to veronica's area, it involves understanding, spoken and written language.
17:40 patient hears the voice or sees the but cannot make sense of the
17:46 So it broke this area, which very close to mona cortex is involved
17:50 the production of speech and moving the blaring sunday sound box veronica's area which
17:59 located to the temporal lobe which is in auditory for hearing Veronica's area and
18:07 two barnacles area. The results and . So these early localizations of specific
18:16 functions are really following brain injuries. , so the way that we understand
18:25 brain is if there is a if there's an injury and there is
18:29 loss of function in this case the of function is to express words and
18:33 of function is to listen to But this is the early really identification
18:39 understanding the damage in the brain or of the brain or cutting little pieces
18:45 the brain and seeing what effect it on on on on functions and loss
18:52 function in particular. There's also an Indonesia Malaysia. At least severe form
18:58 aphasia where you have difficulty in using names for particular objects, people,
19:03 are advanced, so it's not really very defined area, but there's multiple
19:11 areas as you're learning on the left of the brain Broca's area burning this
19:16 . And if you have extensive damage the speech areas you may have global
19:22 . It's severe and extensive damage to language areas that patients lose. Almost
19:28 language function both comprehension and expression, cannot speak, understand write or
19:36 So there is again, the extent the damage is importance of the larger
19:41 damage of course across speech areas, larger the loss of function, but
19:46 the same time specific areas in the and then this gets the left hemispheric
19:51 areas where specific areas linked to the cortex are responsible for production of
19:57 Other areas like Copernicus list linked to to speeches for reception of speech and
20:05 linked to specific loss of function or dysfunctions, abnormalities such as expressive or
20:13 aphasia. Then we come to this which is perhaps the most famous person
20:24 in neuroscience subject. Dennis gauge in is working as an explosive master and
20:33 that time there's a lot of explosions on in New England. They're laying
20:40 and they're laying those railroads cutting through mountains and as they're cutting through the
20:46 they have to pack the explosives and the rocks and move them out of
20:51 way. And so if there's gauges explosives with this. This is a
20:58 of Phineas gauge. He's packing the with this metal dagger here. And
21:04 you can see this is Dennis so he's missing one eye. He's
21:11 this dagger which is an explosive metal dagger. What happens is there is
21:17 accident and the explosives go off by and as the explosives go off by
21:26 , you have this metal uh stick penetrating from underneath his cheekbone and exiting
21:36 taking out his eyeballs and exiting out the top of the skull, through
21:41 frontal love here. Mhm So this is a significant amount of
21:48 And then you would say, well person is probably going to be
21:52 Well he survived and he would say person would probably had massive loss of
21:57 . He probably couldn't walk and he speak and he couldn't do multiple things
22:02 it turns out that's not the And then there's gauge and this is
22:05 reconstruction of the scholar and the damage he had in the skull to the
22:09 and also the actual skull and the photograph of the man. Finance gauge
22:15 gauge a few months later recovers and back to us for his job.
22:21 to work with explosives. He doesn't his job back, He doesn't get
22:25 job back because he is erratic, is aggressive, he cannot control his
22:36 , he's swearing his employers and he's called go away. So what's the
22:44 in finances gauge? He can still he can walk, he can
22:50 he can understand you can hear all these things but he has lost this
22:57 and control of regression function. And we know that the frontal and prefrontal
23:03 are responsible for some of these executive . So we find out slowly through
23:10 traumatic brain injury cases and loss of cases, How the brain in different
23:18 of the brain are responsible for different . Some parts of the brain are
23:23 for hearing, speech producing speech. parts of the brain are responsible for
23:29 of executive functions, control of the control over emotions. It's a story
23:36 knees gauges mixed. It continues. historians and scientists argue that the damage
23:42 not as extensive as others would like describe it. And others have descriptions
23:47 him getting away somehow. Mexico living a criminal life, potentially murdering
23:54 person or two and then sailing back Mexico to the gulf back maybe into
24:00 meeting to Galveston's. So all of different books and accounts are written on
24:05 . But what what what is important is that he's recovered and he's recovered
24:12 . This loss of function in If you have a damage to your
24:17 or if you have an injury to brain during the early development or during
24:22 early age, you have a much chance of the recovery of the loss
24:27 function. So for example, if have damage, if you have
24:33 if you have traumatic brain injury to language areas in the brain as a
24:38 at a few months of age, weeks of age, there's a good
24:43 there's a good chance that you will recover this function and well, how
24:49 that happen? Because during early development have a significant amount of plasticity from
24:56 brain? S capable of rebuilding, and rearranging its anatomy because of the
25:06 environment that existed during the development. trophic factors, the chemical environment and
25:11 signaling factors that exist there for the to do that. Now, if
25:16 same damage occurred in an adult extensive damage to the language areas.
25:22 plasticity dwindles away with AIDS. That's for example, I always use an
25:30 of brain plasticity and learning the I am myself. uh English is
25:37 second language actually myself came from Lithuania I was 17 and you can still
25:46 the accent that I have and it's I started studying english about six years
25:52 age. So the earlier you start the language, the last you sound
25:59 a foreigner speaking their language. That can have somebody in their thirties and
26:04 come to a different country and start english and they're having extremely difficult and
26:10 may be spending even more time than did in the first grade learning that
26:14 language or when you did in middle , what that is the case.
26:20 the plasticity is not there. It's , it doesn't mean that you cannot
26:26 and memorize things. It's finite what learn and memorize. And you also
26:31 to shed a lot of memories and a lot of things. Let's find
26:34 how much information we can start in brain. Let's find out how much
26:38 and rearrangement there is. But there a whole more, a lot more
26:44 and the environment and the ability to that early developing asia's as opposed to
26:51 the adult life. So the loss function and adults following injuries like that
26:56 be significant. Let's talk about Charles , who as you know, is
27:03 of the major developers of the theory evolution. Uh he talked about the
27:10 of the fittest. He talked about . He talked about how animals have
27:17 adapt to their local environments. Of , he went on these wonderful expeditions
27:26 the coast of Ecuador and the Galapagos , observing animal behavior and their natural
27:35 be birds, uh turtles. And he's discovered is that the same species
27:45 subspecies may live in nearby islands, the difference in the local climate in
27:52 island can start affecting the anatomy of island. So he would be observing
27:58 bird beaks and he would say, , these beaks are a little bit
28:02 from this island versus the other island it's the same bird and that's because
28:06 the environment. And so it's not the beaks that are different. It's
28:10 only that externally certain features anatomical features we have, I don't know that
28:20 different based on the environment, but also the formation of the structures and
28:25 maps and the brain anatomy that is in different species depending on what they
28:33 for living? Okay, so a with a desk for living and for
28:39 . The rat, it has to around, look around and whisk around
28:45 that's what rights do. And rodents whisk around, they feel the local
28:50 . So which part of the brain you think is really sophisticated in
28:55 in this animal? Well, it out that it's a matter of sensory
29:00 that is responsible for this whisking The whisker pad itself, where a
29:07 of the time is dedicated by this whisking and sniffing around. So these
29:13 olfactory bulbs, enormously large olfactory bulbs relatively to the whole size of the
29:20 . So you can see that there's lot of brain tissue dedicated to smelling
29:26 to olfaction. And then inside here will learn that there is a barrel
29:32 where there's actually a dark dot. one of these dark dots represents a
29:37 the whisker pad. So it's a sophisticated anatomical map that you see in
29:44 cortex. This is cortical map represents external features anatomical features such as the
29:51 pattern. Individual whiskers or the size the brain that is dedicated to a
29:57 functions such as all factions compared to rest of the brain. And you
30:01 look above it, the nonhuman primates monkeys and what you see, is
30:06 this is the whole factor about? it really big relatively to the rest
30:11 the size of the brain? So which part of the brain,
30:15 which organs in which sensory organs does animal use more? Is it a
30:22 of us now, are they more ? They're actually more visual. And
30:27 like humans, they will have in exhibit of low but very sophisticated map
30:32 represents visual and navigate. We understand map and the take home message from
30:37 is that the environment of the animal not only going to shape, it's
30:43 anatomical features like the shape of the or the whiskers or shape of the
30:50 , but it's also it's going to reflected internally anatomically. And for a
30:55 of the sensory functions and sensory modalities are necessary for the animal's survival and
31:01 . There's going to be larger areas the brain dedicated to those particular functions
31:07 the areas of the brain that will refined and will have, they're more
31:11 . Our biological structures are going to again, four the uh functions and
31:18 modalities that that particular animal is using their particular environment. Now we are
31:27 course very interested to know what different of the brain do, but we
31:31 want to know the precise anatomy and of the south of the brain.
31:38 so we introduced this subject of your and sophomore apology Prior to the 19th
31:45 microscopes were for optical quality. The microscopes capable of resolving individual selves became
31:52 in 1820. Okay, So until , you really cannot see individual
32:05 Individual cells approximately term micro meters micro In diameter. Okay, 10 micrometers
32:17 diameter. And you cannot see that the 19th century. And so there's
32:21 raging debate that's going on. In early 19th century, anonymous noticed that
32:28 brain appeared like a capital very vascular for neural fibers. In the late
32:34 century, many in your anonymous supported ridiculous theory which held the nervous system
32:39 a sense issue. The network of material, having multiple nuclei And cytoplasmic
32:49 from one place in the network to . So particular theories, you take
32:55 brain out and because you don't have microscope, you even if you have
32:59 microscope now, the problem with the is how do you visualize individual
33:05 You have two slices like bread into so you can see individual cells.
33:09 those slices. The problem is the is translucent, so you really cannot
33:15 individual neuron. So you have to some sort of a stain in order
33:18 reveal individual neuronal anatomy. And because lot of scientists amount dissecting the brands
33:26 at the brands and they're like, , it looks like it's all
33:29 We understand there's many cells in there many thousands millions, they don't know
33:34 many nuclei now knows billions of neurons that they all have one continuous cytoplasmic
33:43 . One side applies of sheep is sense issue, the opposing view in
33:48 field is neuron doctrine in other terms known as self theory. It is
33:55 that the nervous system, like all biological tissues, is composed of
33:59 discrete cells. Individual south, discrete of there is a distance space between
34:06 called neurons. Each with just one and surrounded by cell membrane. So
34:12 not all surrounded by one membrane, each one of the discrete unit surrounded
34:17 sound membrane is physically apart from another unit. There are three very important
34:25 that led to the development of modern . On the left. You have
34:30 two million golgi year in the you have Ramona ca hall on the
34:36 , you have Charles. Sherington Communal published a method in 1873 based on
34:46 . Re agents used in photographic development standing Euro. So this is a
34:52 cool thing you can do as a . So it's 1870s. And you're
34:56 that there is some photography things going . People are flying silver nitrate silver
35:04 on these paper and exposing it to light of flying with silver nitrate stain
35:10 getting photographs, wow ! So he , well, can I take that
35:14 apply it on the brain? Whatever nitrate saying, And so familiar,
35:20 applies it on the brain. And discovers the Golgi stain gets picked up
35:26 a very small fraction of neurons in brain, one to few percentages of
35:33 . But when the stain gets picked by these neurons it exposes the entire
35:38 anatomy of these cells. You can the soulfulness of these cells, you
35:43 visualize the dendrites and the accents of cells. So Ramona alcohol, perhaps
35:50 most famous spanish neuroscientist uses this drawing of the microscope that is referred to
35:59 camera lucida. He places a piece the stained brain tissue underneath the
36:05 P. S. Here and he into this I. P.
36:07 And there's a mirror here and that reflects his hands. So basically he
36:14 the ability to look at the stained and by hand he makes these beautiful
36:22 to this day every neuroscientist knows about shows them um with big pride.
36:31 ra Monica Hall is really ahead of started. Okay. and in
36:40 Camelia Golden publishes the But we do visualize individual neurons without any state until
36:48 when there is an electron microscope. huh. There's more information here about
36:54 guys. So community goals. He in particular theater. Can you believe
36:58 ? This is the guy that discovered stain that shows this, right?
37:05 neurons with their processes. But he that the brain is one continuous side
37:11 plaza since issue, his student Ramona believes in neuron doctrine very forward
37:21 He not only draws these networks, talks about things that are very,
37:27 modern to his day. So in brown color. He draws dendrites and
37:34 . And he puts these Arabs and says, you know what these live
37:38 done breeds? They look sort of antennas and what do antennas do?
37:44 , they received the information. So postulated, Okay, so these damn
37:49 here and the apex and here at base and light brown and the soma
37:54 receive that information somehow this information will through the selma in this area like
38:01 . And these black processes that he . They represent axons. So these
38:06 axonal projections. So he said that will flow into them rights. And
38:11 much somehow we'll make some sort of decision in sending that information down
38:17 And then the axons will form these connections to other neurons that Sir Child
38:25 later described and calling the term as synapses is very specialized location between two
38:32 , a place of contact between two . Why was Ramona ca HASA ahead
38:38 this time because he actually thought that connections can be reshaped that these connections
38:46 neurons are not permanent. In reality was And 120 30 years ago talking
38:57 and writing about synaptic plasticity about the of synopses, strengthening of the synopsis
39:04 weakening of the synopsis and Charles. is really coining this term and zoning
39:10 on the specialized area between two neurons that's why he is credited with coining
39:16 describing the terms as a synapse 1906 , alcohol and Camillo golgi together except
39:29 normal prize. But they remain rivals the end rivals on their arguments and
39:38 differences. one believing in particular theory the other one in the neuron dark
39:46 , a very important lesson to learn , late middle of your career.
39:52 matter where you are. You're strong , you're talented, you're dedicated.
39:59 . For some strong convictions, dedicated, he invented the stand,
40:03 is his boss, but he went the grain, he wants against his
40:09 thinking and he says, I'm going think differently, I'm gonna be with
40:13 doctrine, I'm going to come up all of these arrows and plasticity ideas
40:17 all of that. And that's a because sometimes you will be working for
40:24 and maybe that person has a different or different beliefs. There's nothing wrong
40:30 having that. But you can think . And you can be innovative.
40:36 as it's shown many times, you turn off right meaning that these neurons
40:43 discrete units, that there is no doctrine that they have a distinct area
40:49 the synapse and communication between them. is all in 1906. remember in
40:56 , Luigi Golani said that nerves can electric electricity, but we cannot record
41:03 electricity. And we do not know neurons generate action potentials in particular is
41:09 fast fluctuations and number and potential Until another 40 years from when these Giants
41:17 their Nobel Prize. Um All of takes time and the the game in
41:27 brain is mainly in the stain, like the rain in spain is mostly
41:35 the plane the gain and the brain mostly in the stain because the brain
41:41 is translucent. So when Camelia goldie up with the Golgi stain, golgi
41:46 is still being used to this but we still don't understand why.
41:49 a fraction of the south will pick up. We still don't understand
41:54 but we also know still can visualize beautiful process is very precise anatomy.
42:00 of the dendrites axons, all of branching selma's and so on. Another
42:07 . To the brain is the stained called missile stained by franz missile missile
42:15 . In contrast to the golgi Missile stain will stain all of the
42:24 and all of the glia also. goldy stained. Only a fraction of
42:31 will pick up. But you will all of the processes with nestle
42:36 You can very clearly visualize cell cell . But it is a very poor
42:42 to visualize and study neuronal processes such dendrites and axons. So what nestle
42:48 is really good for. Is this see this very dark band here in
42:54 blue narrow here this year on the is a structure that's called the
43:01 And this very dark band running through like a channel. Okay this very
43:06 band indicates that there's a very high of so much neuronal so much that
43:12 located. This is the major layer the parameter dolly layer of the hippocampus
43:18 you have your amital cells that you learn what they do and their
43:23 And you learn more about hippocampus and circuits also. And then you can
43:29 this other band it's called dente gyros it's not as densely populated so it's
43:35 as dark. And then you can that the cells dispersed around in this
43:42 where you can now visualize individual dots individual neurons. The so this will
43:50 you very nicely the site of the whole architecture or the building of
43:56 structures and revealing the cellular anatomy underneath structures. This area of the brain
44:06 called. The lateral gene regulates nucleus the salome's. For the L.
44:10 . M. And right now for it's it's a mouthful lateral june immaculate
44:17 of the thalamus. But after we're studying the visual system you will learn
44:23 this nucleus processes visual information And that are six layers in this nucleus and
44:30 ask yourself and they have to back a little bit from the screen.
44:34 yourself can you see six layers in structure here on the lot. Their
44:41 one 23 war five and six So nestle stain is really great to
44:53 where all of the south, where of the neurons where all of the
44:57 are located, how they're densely they're . What is their architecture? Is
45:05 one layer three layers or as the may be in the cortex there are
45:10 layers in the neocortex. As you learn. It's a very important tool
45:15 describing the cider architecture and so dr through our dreams At the late of
45:22 19th century and beginning of the 20th uses Nestle Stain and derives the subtitle
45:31 . Tronic method cycle architecture cycle location the of the bodies of the cells
45:40 the architecture. Different functional areas are by observing variations in the structure of
45:47 self, the virginian. Broadmoor accuses stain And this will stay and by
45:54 way, can distinguish between glia and . It's not an ideal tool but
45:59 can remember. This will stain, not show you the processes the dendrites
46:03 axons as goldie staying well. And is the convenient broad ones areas for
46:09 missile stains. So you can look and see which area do you think
46:13 Broca's area? Which area do you is Monica's area? And these areas
46:19 are labeled by rebellion broadband for Area 17 if anybody tells any
46:25 Area 17 Oh you mean the primary cortex for area of view one was
46:30 knowing by those names. So what did very precisely stay in the entire
46:36 and slices and reconstructed the anatomy of entire human brain basically based on the
46:43 of the architecture. So the sight architect tonic methods which shows you essentially
46:49 this very complex building is built with floors and different garages and entrances and
46:57 and roads into connecting and in certain and densities of the buildings and so
47:04 . Now modern day microscopy and standard microscope you can get a resolution of
47:10 zero point for micro meter. Um you can visualize individual neurons and there's
47:18 methods not individual to visualize individual neurons using a stain that I'll describe to
47:24 a little later. The reality is the synapse or the space between neurons
47:30 only 29. So a standard live cannot resolve the span between neurons that
47:38 visualize synopses. And in order to synopses we need to use electron microscopes
47:45 microscope has a resolution of 0.1 And using electron microscope which came out
47:53 the 1950s we were able to start without using stains individual cells and individual
48:03 . What what is depicted here on ride? Is it done drive?
48:08 odd of this dendrite you have these protrusions. There's a member nous protrusions
48:13 come out of the membranes that come form what we call the dendritic
48:19 So this is done dR. N. This is mitochondria and the
48:24 . He is the stands for post density on these dendritic spines. You
48:29 have receptors neurotransmitter receptors. Chemical receptors are located on these membranes juxtaposed on
48:37 right side. Here in red is axon of another neurons. So you
48:42 actually very discreetly see the synapse You can see the neuron with the
48:48 and the axon of these red dots the little red circles our neurotransmitter vesicles
48:56 our vaccine all terminals. And you see these vesicles are actually using to
49:00 plasma membrane and on a more zoomed level you would be able to see
49:06 these vesicles are traveling across the plasma and into the synaptic space of its
49:13 synaptic collapse and then binding to the synaptic density of receptors pasta in
49:19 So dendritic spines are the most plastic that you have in the brain so
49:27 can change their shape. They can their numbers and they actually come in
49:32 shapes. So they hear described this study spine. Be a thin
49:37 See a mushroom shaped spine. So have different descriptions. They have different
49:45 in different colors shown here. They different densities along them rights And it's
49:51 important for learning and memory and for communications is the great expanse for most
49:58 the contacts where most of the inputs synapses between neurons axons and dendrites and
50:05 spines are formed of course the modern microscopy. You also have a focal
50:13 . We don't have much time to the amount of different microscopic techniques but
50:18 has a resolution to visualize individual There's fluorescent con focal microscope that can
50:25 you visualize and then expands and visualize synopsis as well. So this is
50:33 three D rendering of the dendritic spines the dendritic spines work life. This
50:39 shows that Even the 19th and beginning the 20th century we needed to have
50:45 stain in order to gain an understanding the brain and visualized brain. In
50:50 20 the end of the 20th middle of the 20th century we came
50:56 with a technique that is called infrared . R. Infrared contrast microscopy.
51:02 a sample of the brain tissue is underneath the ones here underneath the objective
51:08 the microscope and it's being illuminated with certain life. And that information being
51:16 through a number of democratic mirrors and funnels out the signal that's an infrared
51:24 the infrared camera will pick up the and you can actually visualize individual neurons
51:30 the state. Okay so the take message is that if you want to
51:35 the precise and animated and the dendritic and then the very spines of individual
51:41 . You would use Goldie states. you are looking at the general cider
51:46 . The layering the densities of the . You want to count the soma
51:50 of neurons and glia distinguished between neurons glia. He will use a missile
51:57 if you're not staining anything and you to visualize neurons in slices. So
52:03 is in the petro their microscope. can use infrared microscopy and by using
52:09 microscopy and infrared cameras, you actually individual neurons. And underneath this microscope
52:16 also have micro electorate holders and those holders can hold tiny glass micro electives
52:24 these tiny glass micro electors using techniques are called electrophysiology. It's a very
52:30 way of biophysics really. And then biophysics electrophysiology. We can approach and
52:38 individual neurons. We can approach and activity from individual neurons or from networks
52:45 neurons using these different micro electrodes. so you will learn about different micro
52:52 recording techniques and neurons in the brain are used to study activity of individual
52:58 as well as the activity of networks neurons. And this type of technique
53:03 necessary in order to record action And so we'll talk about how the
53:08 action potentials were recorded using much larger . These are cells that are in
53:14 brains about 10 micrometers in diameter and axons are very, very small.
53:20 axons. You can't really barely see . You can see the larger than
53:25 the axons are about one micrometer, micro meter or so or less in
53:31 . So you can barely visualize them diameter of the tip of the
53:35 It is about 1 to 2 micrometers diameter and so the diameter of the
53:40 is about 10 micrometers. These are very good scales to keep in
53:46 What is the current view of While the current view of neuroscience is
53:51 we know that different parts of the are responsible for different functions and we
53:58 have the ability to actually look inside brain and look into the different parts
54:04 the brain and how they function without a brain transformation of cutting into the
54:10 tissue. But using imaging techniques, such imaging techniques that allows non invasively
54:18 the skull visualized activity in the brain called positron emission tomography or pet scans
54:26 positron emission tomography which will study the later it will basically reveal the
54:32 If you image the brain and the who's looking at the words then the
54:36 lobe is involved. But you can when the person starts listening to the
54:40 and more of the temporal lobe. vernon cas area is involved when the
54:45 one is speaking words, the motor and the Broca's areas are activated
54:52 So these read maps these red and maps indicate heightened levels of activity compared
55:00 the rest of the activity in the . Now notice thinking of the
55:04 Thinking of the words involves many different of comprehension, speech production and other
55:11 such as memory and emotional centers as as you speak certain words. And
55:17 modern day we call these brain maps brain maps or brain activity maps really
55:24 the underlying structure of the south that underneath and their physical properties and ability
55:29 produce different types of signals of different . And modern view is such that
55:36 understand individual synopsis. We can actually individuals and expands. We can visualize
55:43 synopsis, we can individualize individual molecules molecules in the synapses. These techniques
55:51 now, of course, if you to visualize neurons to such great detail
55:55 invasive techniques. Their in vitro nearly in animal models, mostly in vitro
56:01 in vivo. That's a very limited . And on the other spectrum we
56:07 the clinical techniques for imaging brain activity invasively in the hospital such as
56:13 I functional magnetic resonance imaging or attacked emission tomography. And these are on
56:21 gross scale and the gross anatomical scale showing you the activity masks that are
56:27 with different tasks in the brain. 20th first century I believe is heading
56:34 we're going to be able to see synoptic activity In the brain's non invasively
56:41 we imaged the entire activity of the . This is the challenge for the
56:46 assumption. You're going to be part the solution so that you can non
56:50 track either single molecules for single synopsis compute billions and trillions of active synapses
56:59 the same time, understand the overall and then come up with different solutions
57:05 are pharmacological and therapeutic solutions to problems that people may have um in their
57:13 dysfunctions. So current view is imaging that show the brain functions. Certain
57:20 are carried out in the specific areas the brain. Each function is observed
57:25 more than €1 toppling when one pathway damaged, others may compensate, making
57:32 harder to see emotions are also We have temporal lobe epilepsy and micro
57:39 . There's certain parts of the temporal that are connected to emotional centers and
57:44 processing system. And so if you a temporal lobe epilepsy and there's abnormal
57:50 in the temporal lobe, it will evoked very strong emotions. You can
57:54 remote evoke emotions by micro stimulation. there is a seed for all of
58:00 things. It doesn't mean it's just in one spot. But there's systems
58:05 that that processing emotional information off as , they're localized. So imaging reveals
58:14 different processes called elementary operations processing in brain is both serial and parallel.
58:21 you have parallel processors like you have your computer, you have redundancy redundancy
58:26 important. Several faculties, several several subtypes of cells of processing similar
58:32 same type of information. Several chemicals responsible for similar the same type of
58:39 and that is because if you have loss of function. If you have
58:42 damage to the brain, there's a and the way for other chemicals and
58:47 brain parts to still convey at least limited uh part of that information that
58:54 have been impaired during the downers. the simplest multiple activity requires coordination of
59:01 in multiple areas of the brain. thinking of the words you will
59:06 oh well it's a lot, it's multiple areas of the brain involved.
59:10 course A lot of times we get question, do we only use 10%
59:14 our brain, professor? Well, know what? You can use 1%
59:19 your brain if you like. And a way that the brain can get
59:24 . 200%. And that is called Grand Mal epileptic seizure and you should
59:28 in the hospital in the emergency So how much percentage of the brain
59:32 activated? How much of it are taking advantage of? From 0 to
59:38 is the answer. And it just the complexity of the task, the
59:42 of the task and the focus focus the unitary focus or divided. Focus
59:47 different tasks which will involve different parts the brand communication between them. So
59:54 process that we we think about thinking that coordinates activity between multiple brain centers
60:01 very seamless to us. We don't about it. We don't think about
60:05 about it. We just think about . We think about words and then
60:08 words interestingly enough, if you surround with a virtual environment, this is
60:13 coming into play because the future of is not only going to be In
60:18 wet labs, the future of neuroscience neuropsychology, pharmacology is going to be
60:24 the virtual reality as well through augmented . And some of you in another
60:30 , 15, 20 years will have place in the metaverse. And interestingly
60:36 , when you place the brain in reality, when you place the brain
60:40 these alternate versus matter universes, you are changing the brain maps as
60:47 So there's no virtual reality here and is the brain map recorded from this
60:52 and then this individual gets submerged from virtual reality of The Snowman. It's
60:57 game that was actually here at the of Contemporary Arts in Houston. Fantastic
61:02 free to visit. Don't forget the museums here in Houston. They're free
61:07 Thursdays by the way. So if don't have any classes someday, you
61:12 we'll visit all of the Museum of Art of Houston and everything. And
61:16 not saying you will find the stuff , but you'll find some very interesting
61:20 in there with virtual reality. You an individual to virtual reality and you
61:25 his brain maps if you alter its activity, there's something to be said
61:31 that was something to be thought about . And as you listen to matter
61:36 matter verse and all of these verses . Think about the future of neuroscience
61:41 much of it is going to be in non invasively understanding the brain activity
61:46 it is placed and augmented or virtual . So potentially recreating these brain maps
61:53 external stimuli and such without having that reality. So some things to think
62:01 in general, these are the medical of the nervous system. So you
62:06 have heard what is a neurologist is specialist neurologist deals with diseases of the
62:11 system and their specialist. So you have a neurologist that specializes in
62:17 You can have a neurologist that specializes Parkinson's disease or motor disorders. You
62:23 have a neurologist that specializes in autism many different neurological disorders and migrants.
62:33 so the neurologist is a person that the disease of the nervous nervous system
62:39 an MD. The psychiatrist is also M. D. And is a
62:45 and personality disorder. Person Neurosurgeon is surgery of the brain and spinal
62:53 So it's about 10 year residency I to become a neurosurgeon. But you
62:58 are now cutting into the tissue and cord and the brain and you do
63:04 surgeries of course you have brain You want to eliminate certain tissues that
63:10 been damaged by trauma or if you inflammation or infection that is spreading.
63:16 is when you reserve two brain neuropathologist would study tissue to identify changes
63:24 the tissue of pathology in the tissue you can be MD or PhD to
63:30 a neuropathologist. And I've seen very phds running departments and the hospitals as
63:37 neuropathologist studying. You can be a in this case for the brain in
63:42 . You can have pathological labs that changes in tissue across different organs when
63:47 liver, kidney and so on with . Specifically focused on any tissue changes
63:53 the brain, experimental neuroscientists. So is something that I am. I'm
64:00 experimental neuroscientist and also thinker from experimental of a neurophysiologist, neuro pharmacologist and
64:09 anonymous these are my strongest innate faculties the pulmonologist told me by looking at
64:17 skull bonds. Just kidding. It me years to get where I am
64:22 I'm learning every day. I'm also a lot of biomolecular computational neuroscience.
64:28 is computational renaissance that's not poking the into the tissue or doing any dissections
64:34 actually using mathematics and mathematical interpretation of with the brain activity in the
64:42 So you can say non tissue touching , biological psychologist, psycho physicists of
64:49 of these are kind of experimental neuroscience and multiple levels of an office is
64:55 you can analyze things in the molecular . I'm really interested in this molecule
65:00 this. You know, chinese a in chinese. A and and then
65:05 in the molecular pathways or I'm really in the cells are are cells communicate
65:11 each other in the cellular level. interested in systems. I want to
65:15 how the visual system works. So not studying one molecule but rather than
65:20 visual images to the visual system of to study navy visual system non invasively
65:26 partially in basically behavioral studying animals learning, anxiety, exploration, load
65:37 behaviors, cognitive levels of analysis to cognitive neuroscience which I would say is
65:44 closest to logic, closest to philosophy psychology More so than to the wet
65:52 scientist. As I would say biophysical . Thanks So you have the mental
65:59 . They're anonymous all of these different . And the reason why I show
66:03 slide is because to give you an that as you learn neuroscience and as
66:08 take information from the sports you can able to apply to many different areas
66:13 if you stick with neuroscience you're not to just be a neurophysiologist for DNA
66:18 anonymously actually can have incredible mathematical skills not have let lab skills would not
66:26 to work with animals for some But be brilliant computational neuroscientist bouncing in
66:32 field because the processes in the biology the math. But then the math
66:40 advances and models the processes which informs experimentalists and informs the um medical doctors
66:50 the potential models of the future and treatments where they're not readily available to
66:55 performed in the lab or during very times of developing drugs not available to
67:01 through fully through clinical trials. We to advance some of these things much
67:05 . And you can use computation so can use computation now to determine the
67:10 of the proteins that is much better using experimental techniques of X ray crystallography
67:17 you'll learn about later. And the being is that it's actually more accurate
67:22 experimental techniques, Sometimes computational experiments. with this slide I will uh leave
67:32 in this lecture. Thank you for here. I'm gonna stop the
67:39 This concludes our electric too. And will take an in questions and look
67:45 at the chat after I stopped the
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