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00:00 Okay, this is lecture 14 of and we will start discussing the central

00:08 system some basic concepts and the development the central nervous system. Some structures

00:15 functions of the major parts of the . N. S. As

00:19 So if you look at this diagram this uh section will have a lot

00:27 diagrams and typically on exam two I quite a few questions on labeling that

00:32 related to the brain parts and And you should note the parts and

00:39 functions because the questions may ask you the function to point to certain part

00:43 the opposite may pointed to certain part see what is the function of this

00:48 part of the brain or or nucleus such. So on the left,

00:53 you have is you have different animal from rat to dolphin aligned in

01:02 So this is to scale on the and you can see that rat brain

01:08 barely just a centimeter and some, dolphin brains are actually larger. And

01:18 we look at this and we should fern ologists, the dolphins are smarter

01:25 humans because they measured it partly by size of the organ. So uh

01:32 would be smarter than humans too. some basic features that repeat in these

01:39 brains here, it's no longer to . But here it's to show you

01:44 larger images how they differ that if look at the human brain it has

01:52 complex imaginations and Rijs. They're called and Joy ride. You see that

02:02 structure in other animals and dolphins. then you look at more primitive animals

02:09 you see that they don't have this and gyros structure, rodents or it's

02:17 limited what these salsa do. They change the positioning. The architectural positioning

02:26 neural networks, increases the surface area increases the complexity of the brain

02:35 And so english language, there's sometimes saying a lizard brain or smooth brain

02:42 the lizard brain. A smooth brain to a smooth brain that has no

02:48 and dry, right and really kind a simplistic attitude. Uh Forward life

02:54 problem solving as it is being used , uh you can see that certain

03:01 will have certain structures that are much relatively to the rest of the size

03:06 the brain, rats and rabbits. can see they have these huge olfactory

03:12 in the front and that's a factory . So a sense of smell and

03:18 lot of the brain area. A of its mass is dedicated to

03:24 You can see that when you look the humans, you will see these

03:29 olfactory bulbs, you can barely identify here in this diagram. Here's olfactory

03:34 in dolphin there even larger here but still very small compared to the rest

03:38 the size of the brain and then parts of the brain are developed differently

03:44 animals. So the dolphins will have very large served malum referred to also

03:50 a little brain. Humans will have sizable cerebellum too. Um But here

03:56 can see cerebellum is almost like half the massive and C. N.

04:01 . So there's certain functions that these are performing. There are certain sensory

04:08 such as hearing that is improved in animals are superior even to humans.

04:16 of smell in certain animals, superior humans. But we still find ourselves

04:24 the top of the food chain, to mars and playing politics and really

04:36 , ruling the rest of the animal uh collectively on your own, if

04:43 in the forest, you're pretty helpless the rest of animal kingdom and your

04:48 may not save you. But these that you see in the brains are

04:55 changing throughout evolution. So how the looks like, how the circuits are

05:02 the brain, what parts of the are accentuated certain animals. It has

05:06 do with evolution has to do with environmental changes. It has to do

05:10 the ability to procreate and survive. we talk about anatomy and brain anatomy

05:19 structures. We always have to refer to some of the basic concepts some

05:23 those concepts, medical concepts you may learned, such as on the orientation

05:30 planes through the brain, the cutting through the brain. So the front

05:37 inferior for rasta rel the back is end that the back because this is

05:44 back, the back is dorsal, chest area is ventral access here and

05:54 tail is posterior coddle media was in middle and lateral is away from the

06:04 . And there's a lot of brain that are named after their location,

06:09 lateral nucleus or so and such. you're gonna look somewhere in the middle

06:14 a little bit off the middle laterally identify certain nucleus. Then you have

06:21 planes through which you can cut the to visualize the inside of the brain

06:27 all of the structures the cut that it in between you can say between

06:33 and advances from media or midline to lateral aspects you referred to as miss

06:41 cuts that really roster to carl. if you cut the brain in this

06:49 , this is horizontal orientation and this orientation as we purchase kurono orientation,

06:57 cuts and how this came about is we were interested to know how different

07:05 in the brain looked like traditionally. you learned there was nestle stain and

07:10 will stain. Will stay in all the neurons and glia and show you

07:13 cider architecture. So you want to that side of architecture in three dimensions

07:18 this plane and this plane that And then you can reconstruct three dimensions

07:24 these different structures. Uh your anatomist these as their maps. So somebody

07:31 to tell me you're looking at the sagittal section of a mouse brain and

07:37 give me coordinates let's say half a apart from midline I place in my

07:44 approximately what part of the brain or structure of the brain we're looking we're

07:48 about are looking at just by getting coordinates and placing them in my mind

07:53 where they are. So we use as maps. Now. You take

07:57 map of campus and you say this the building here, this is the

08:01 here, this is the student this is the dorms here. So

08:05 use it as a map. Also these different cuts will give you a

08:09 representation of this map essentially giving you dimensional representations. So cerebral hemisphere.

08:17 cerebral we have lateralization of brain Right brain, the right hemisphere and

08:24 cerebral hemisphere. They're responsible for slightly functions. Advanced processing, different

08:30 cognitive functions and even sensory remember, this area was on this side.

08:36 . And we we we saw that clearly it wasn't shown on the right

08:41 of the brain. So there's other of cognitive and processing capabilities that are

08:47 . Ized and to the hemisphere. stem is sort of the core of

08:53 brain that's holding the brain and evolutionarily was the original first structure that was

09:00 in the C. N. And these other structures cerebellum. Sub

09:04 structures such as the thalamus and Finally culminating with neocortex as the most

09:13 advanced and most sophisticated neural circuits in brain. So cerebellum, cerebrum and

09:24 hemispheres. The process information contra laterally they send the motor signals contra

09:33 So a lot of sensor information will this hand, right hand will cross

09:39 the left side of the brain and I'm moving my right hand, that

09:44 my left motor cortex is telling my hand to move my right motor cortex

09:49 telling my left hand to move cerebellum the other hand will process. One

09:55 the functions of cerebellum is movement control it will adjust that on the same

10:02 which is referred to as iptc lateral . So left cerebellum will control movement

10:07 on the left, right on the side. Brain stem is where you

10:13 a lot of the cerebral to sarah between cerebrum and cerebellum, the cerebral

10:21 and cerebellum and between cerebellum and So a lot of the connections these

10:28 areas are very much interconnected. A of these connections are gonna be running

10:32 brain step brainstem will also contain nuclei are responsible for the vital body functions

10:42 what you've learned in the neuro transmission is that brainstem will also contain these

10:48 that specifically express subtypes of a means we looked at such as norepinephrine dopamine

10:57 scattered through brainstem as we saw in diagrams from last lecture, but brainstem

11:05 contain nuclear that responsible for vital body , breathing consciousness control of body temperature

11:15 uh supposedly maybe this is all you to survive. Originally before you become

11:21 very complex cognitively animal and it gets you know democratic or Republican party left

11:29 right right. So uh this was core of the brain that existed

11:36 More complex structures evolved with time and peripheral nervous system. We don't spend

11:46 time. But you have a somatic is voluntary motor and sensory skin joints

11:53 muscles. But you also have a peripheral nervous system which is a lot

12:00 times referred to as autonomic nervous And this is really the nervous system

12:05 innovates your guts not your motor and . The motor and sensory we discussed

12:12 the reflex arch from the spinal But the visceral autonomic nervous system is

12:19 of nerve endings throughout organs, internal , blood vessels, glands and very

12:28 so very sophisticated. Mesen terek autonomic system which is basically the gut or

12:35 digestive nervous system. And what's emerging this nervous system and the gut is

12:42 potentially it is as complex with as players and synapses in ways of communicating

12:49 the periphery as it is in the and the C. M.

12:54 And this is a really interesting emergent of study how the god affects the

13:01 . How the nervous system of the is related to the C.

13:06 S. How the microbiome of the where you carry a lot of bacteria

13:14 probiotics in your gut that are very that they not only help your digestive

13:21 but sometimes they produce their own Metabolites could even cause neurodegenerative neurological complications

13:29 your gut. This is a very field emerging of microbiome the nervous system

13:36 connected to the microbiome and how this system is enteric is communicating to the

13:43 . N. S. And what they have on each other. The

13:49 is protected by the men injuries. have three men injuries. So after

13:55 remove the skull you are encountering the surface. Meninges is due Ramada which

14:04 hard mother. And subdural space here the dura mater is spilled with arachnoid

14:15 . They're also meninges and membranes that spider like productions. And the closest

14:23 right on top of the brain Most internal is the PM. Modern

14:29 the or the gentle mother. So men in jeez they are protective.

14:36 physically protective. Uh Dura mater is tough. It's like a skin.

14:45 you you have to you cannot penetrate dura mater. Just with the finger

14:50 have to use a scalpel in order cut through dura mater uh in this

14:57 you have fluids so it's kind of fluid. It's gel like environment.

15:04 then you have a cushion here. if the brain squeezes you have physical

15:08 . You have the arachnoid that can squeezed and change its shape a little

15:13 . And then you have the M. On it. They not

15:16 protect but they also nourish the brain can be a source of nutrients,

15:23 the PM. Otto. When we in the first lecture, the brain

15:29 nations. And we said that these prehistoric cultures that were performing brain

15:37 they were potentially the first neurosurgeons. as you can see underneath the dura

15:43 , you have larger blood vessels that the smaller micro vessels that penetrate throughout

15:52 the brain tissue. And there are where these vessels can rupture. It's

16:01 stroke or it can be an aneurysm normal formation in the blood vessel and

16:08 the blood vessel. And what would then is that you would have what

16:13 called a subdural hematoma. So if blood vessel ruptures and they have coagulants

16:21 the blood and the coagulants at the of the coagulants is to stop the

16:27 , is to thicken the blood and of that blood and stopping the bleed

16:33 create a thickened kind of a blood that is referred to as a

16:39 And you can have him a thomas on your arms and your legs where

16:44 have the bleed and you can see bruises for example. So this would

16:48 on the inside soda really. And only way that you could clear that

16:57 would be by opening the skull making incision in dura mater and clearing physically

17:04 that wound. Just like you would this in fact and patch up the

17:09 on a hand or a leg or part of the body. So if

17:15 don't clear hematoma, what can happen the pressure may build up and they

17:22 causing pain and it may start causing problems down down the road, like

17:29 and potentially neuro degeneration in the area the area of the injury. So

17:34 want to clean up that area and why you had potential interpretations. That's

17:40 interpretations potentially were repeated. Because some these problems where either chronic or recurrent

17:47 that needed attention multiple times through this . Yeah. Do they do they

17:57 ? That's a they don't degenerate the way that neurons would degenerate. There's

18:04 sis in the crisis that happens in but there's definitely aware down of the

18:09 injuries. But I'm not very familiar how they degenerate. It's more of

18:14 structural breakdown and in the actual Oh do they grow back?

18:24 Actually you can suture some of the modern dura mater especially you can suture

18:30 some of the PM. Modern and would would be belt. Yeah.

18:34 was thinking more when you ask that whether they degenerate with age kind of

18:39 know, become very thin and go . So good question. So ventricular

18:46 , we have the supply of cerebrospinal CSF cerebral spinal fluid that bathes cerebral

18:54 the spine it's produced in this area lateral ventricles that has core oid plexus

19:02 produces the cerebrospinal fluid. Cerebrospinal fluid circulating through this ventricular system that is

19:10 the whole brain and inside the spinal . And this is how it provides

19:15 cerebral spinal fluid that bathes the neurons there's constant production of cerebrospinal fluid and

19:23 of that almost on a on a basis where we basically produce new fluids

19:31 and they eventually go into Iraq subarachnoid spaces and get drained. Now,

19:40 there is abnormal formation of fluids, could have a developmental condition which is

19:48 to as hydrocephalus. Okay, what I have here? And brain trapper

19:54 again. So what is hydrocephalus? is a condition where there's too much

20:02 the production of the surplus spinal fluid the draining of the cerebrospinal fluid is

20:07 . If it happens during early developmental it will actually stretch the ventricles will

20:15 them very large. The ventricles will pushing on the brain tissue, will

20:21 the brain tissue and the brain tissue start pushing on the skull and the

20:26 is soft during early development. If recall and mentioned that when newborns are

20:32 , the skull plates are not even and the size of the head is

20:36 big and then by the time you're it's about this big, whatever,

20:44 ? So if that happens and those are not drained properly, there's a

20:51 up of those fluids, they will the head and in the hydrocephalus.

20:58 developmentally patients may end up with this shown here. I don't need to

21:05 with this exaggerated alien, like whatever think of alien heads are egg shaped

21:13 heads that are abnormally large and And how do you treat hydrocephalus?

21:21 insert a tube into the lateral electrical drain the fluids. If it's a

21:26 problem, sometimes you can actually leave tube in the petunia cavity so that

21:33 draining the fluid and you have extra as the child is growing, it's

21:39 to the child's size. Uh, is a rare developmental condition, but

21:49 can also be brought out by So there's this thing that I've learned

21:56 about uh 13 years ago that a baby and shaken baby syndrome can result

22:07 hydrocephalus, shaken baby, shaken baby is usually when parents are very stressed

22:15 and they have newborns and the newborn crying and if the parent is not

22:21 altogether or they're not educated or they're not good people, they start shaking

22:28 babies shut up to sleep off and shaking actually can lead the hydrocephalus is

22:36 condition because it imbalances this mechanical movement the brain, the fluids, the

22:43 of the fluids and can result in condition. Uh Likewise, brain trapper

22:51 , potentially were used to drain those also. So there are some skulls

22:58 are in in in in Children. nations that are found that would suggest

23:02 potentially that was one of the conditions treated in addition to internal bleeding.

23:08 hematomas. I it could be the . Yeah and the lymphatic system it

23:32 could be too much for plucks is producing too much fluid instead of the

23:38 500 ml for a certain amount of is producing 2000 and the drainage system

23:43 working but it's not adjusted to this of the fluid being produced. So

23:54 going to the spinal cord. And so here the drainage actually we don't

24:01 much about the drainage but we'll come to it. I have another whole

24:06 on the ventricle. So we talk how to get to the spinal

24:10 So hang on to that question. look a little bit before we get

24:15 that at the development of the N. S. And how it

24:17 about. So first of all we three for more deal what I call

24:28 really three developmental layers. The Term the term in the end.

24:36 . Um And so when we have three layers it's kind of a this

24:41 called the neural plate and it looks a plate and then that plate starts

24:47 and it actually closes up and forms tube. So this neural tube formation

24:54 also referred to as no relation. end of term will give rise to

25:02 lining of internal organs. Sir. mezza term will result in skeleton bones

25:11 muscles and ectodermal um will produce nervous and skin skin is the largest organ

25:22 the body. And in the very stages of the pleura potency these cells

25:32 capable of becoming either the skin cell No, no. Uh We have

25:38 research here at U. Of When the skin cells of being isolated

25:43 study to produce the progenitors of the of cells, part of the cells

25:49 neurons. Part of the cells become cells. Uh So here you have

25:57 neural play green when neural group neural fold and then finally neural tube

26:06 surrounded by simple minds here and the crest here this process again is no

26:13 and so much that you're seeing here become the vertebral column and scalable

26:22 So this becomes the C. S. And this becomes a vertebral

26:26 column. Now after you have neural formation and during the neural to information

26:35 can have some miss formations of the and these are rare developmental disorders of

26:43 tube formation. But this process, you think about it, it's a

26:49 complex structure in general. From inception sperm meets the egg and there's new

26:58 generator. What happens is self It means that the father and the

27:08 are not saying that I'm gonna put ear next to this here and then

27:12 gonna do this. I'm gonna shape head like this. It's self assembles

27:16 body. The brain self assembles itself this really complex structure. You have

27:21 have the right environment for it internally externally for this development to take place

27:30 and developmental disorders. And maybe one 1000. So the code for self

27:37 is really strong. It's pretty robust . That means that it's not that

27:44 brains always form perfectly. It's just whatever happens in small differences is robust

27:49 not to cause developmental and other But if you have a condition where

28:00 frontal part, the roster, all of the tube is not folded regularly

28:09 not formed normally. You may have condition you cannot survive as anencephaly,

28:16 know, missing that cerebrum or your cerebrum, cerebellum, cerebellum, uh

28:24 cortex. And in other instances if more carnal aspects of this to get

28:36 during the no relation process, you have a condition that is referred to

28:42 to come about. And that is treatable surgically treatable condition. So uh

28:53 they're rare. What happens? What is that there is a very good

29:00 . Thanks for pointing. God is the spinal cord forms this abnormal growth

29:05 it actually sometimes sticks out of the call. So it has to be

29:11 corrected. And I believe that these days they can diagnose it in the

29:16 . And sometimes even perform the procedure the womb too. Don't quote me

29:21 that. But I believe I read this a little while ago For me

29:27 quite remarkable that you have two cells together form a human body but just

29:32 at this millions of cells folding, each other, shaping itself. And

29:39 does it really well the code is . So once you have the plate

29:47 into tube you have more complexity developing the brain and you have information of

29:53 primary and the secondary vesicles, primary of prison cephalon, forebrain. Mesen

30:00 , birdbrain. Now we're looking at divisions of the future. CMS and

30:05 sufferer for the hind brain. So are the primary. Then with some

30:11 this this this shape here frozen cephalon into this shape and differentiate. So

30:19 is now development and differentiation from the from the tube. Primary secondary.

30:26 you differentiated the talents of phallic diets of phallic these are the optic

30:36 students will have the attachment of the . I telling the catholic vesicles become

30:45 cortex. Don cephalon because the part the brain that we call the

30:51 So if you have the optic stock and these optical vesicles and the optic

30:58 of the edge of the optic cup will form the retina. So anybody

31:04 studies the retina or in optometry or neuroscientists because it's a part of the

31:13 routinely is not that other components of eye ball and the eye, but

31:19 retina is okay, okay. file and cephalon, two cerebral hemispheres

31:36 from talent cephalon dying stuff along starts in the high end brain and the

31:45 starts differentiating. You can see that what looks like one structure in the

31:52 . Eventually you form four structures. is on, on the dorsal

32:00 you're looking on the dorsal side of brain and uh what you're seeing basically

32:07 these structures four structures. One of favorite structures in the brain that referred

32:13 as corporate quadra, gemini, corporal, the body quadrille for gemini

32:25 . If anybody is into linguistics or foreign languages and there's more than two

32:30 three languages and this is also a . You always have to take it

32:35 and cut it in pieces. so um that's how you can understand

32:45 easier. There's roots to the their endings to the words of

32:50 But if you go to the you know corpora, corporal, corporate

32:56 something to do with what location or quadra. Four quadra quadra try or

33:08 try would be three by would be what computer received we have again,

33:19 rasta Raul, no factor involves All coddle dan cephalon cerebral hemisphere.

33:30 for labeling questions don't get stuck on image. This is a different orientation

33:36 the previous slide, just learn what structures are and what you're looking at

33:41 factory bumper front, what's the front ? All that's where I am.

33:47 look in previous slides roster was on opposite side of the slide. So

33:52 learn it just by looking in the but learn the three dimensional structure.

33:57 is still in cephalon. Diane the main divisions. Okay And

34:03 You have the formation of the ventricles two lateral ventricles, the third

34:09 You can see the dyin cephalon further into stahl emus and hypothalamus. Very

34:16 parts of the brain. You have basil tellin cephalon. Then you have

34:20 cerebral cortex, basal tellin cephalon also other cortical areas like temporal lobe.

34:27 have corpus callosum here corpus callosum is major fiber track that inter connects the

34:34 hemispheres, the left and the right . So the communication between hemispheres because

34:40 have contra lateral as I said control movement for example it doesn't mean that

34:45 left hemisphere doesn't get that information and that information. There is a connection

34:52 communication between the hemispheres. You have lot of sub cortical e from the

34:59 cephalon especially from the thalamus. You a lot of projections that are wide

35:05 projections. So these are axons that run from the thalamus into the cortex

35:10 they will also run back from the into the thalamus. These projections are

35:16 to as internal capsule and you will these white matters running basically from diane

35:25 into the cortex from back into the and cephalon and that's how the communication

35:30 happening between the sub cortical parts of brain and the cortex. So if

35:35 look at this brain ship enterprise, have talent, cephalon, dying

35:41 This is another representation. You have based on olfactory bulbs. You have

35:47 cephalon which becomes the following. This the following. This is on the

35:52 side and then you have the hypothalamus you have the textile which forms from

36:00 the brain. Tector means the So again it's this side that detect

36:07 . Then you have the tag momentum this side and the ventral side.

36:12 balham around them. Zeppelin hind brain to serve balham and pawns and then

36:19 smallest longest part here. That's the reminiscent of the spinal cord is called

36:24 medulla oblon gata and then subsequently the cord to the ventricles that you have

36:31 running into the lateral ventricle, the and 4th ventricles and then the whole

36:38 supply goes through the spinal canal into spinal cord. So CSF actually will

36:44 in the spinal cord also has its drainage system. With the interesting part

36:50 is that if you wanted to sample fluid you could tap in to the

36:59 . It's called spinal tap and get sample of service spinal fluid and that

37:04 important especially when you are studying or suspect the brain infection in the cns

37:10 infection of the fluid. So we'll back to that in the sacramento.

37:18 once again now we have the mature with complexity with different parts that we're

37:24 at. And now we're going to learning about these different parts of their

37:28 . South side grooves, gyre, ridges, cortex, the seat of

37:35 and ignition. Or can we think our guts? Well, surely our

37:45 can influence our thinking a lot. But if you disconnect for cortex from

37:56 rest of the body, there isn't left. So if the gut is

38:02 it cannot perceive it without the higher and this the brain you have the

38:09 lobes in the front. You have parietal love and the central selfish that

38:16 the two lobes. Here have a . It'll load in the back.

38:20 is a temporal lobe. This is sort of alum. This is a

38:25 dimensional structure of the ventricles and the is the lateral ventricles. And third

38:31 going into the spinal cord, the dimensional structure that's been cut off in

38:37 sort of the rat and human brain there's still a lot of similarities,

38:42 if we're very different animals structurally There's some basic features that are

38:48 You know, we have Madura have pounds. Uh We have third

38:55 We have talent, cephalon, olfactory that's very small. And they have

39:02 factory but it's very very large. there's certain features that we have again

39:08 have developed a lot better in us the animals so that there are certain

39:13 features that are repeated throughout animal So you can take a piece of

39:21 from an alligator with a lot of here or you can take a piece

39:26 cortex from rat. We also have lot of these here too. And

39:29 you take the piece of its new and you stained it with famous stains

39:36 missile stain or golgi stain you would the parameter will sell ethical denver rides

39:41 a certain layer structure. When you in the rodent you would find the

39:46 or very similar looking phenomenal sauce with certain structure. So there is uh

39:55 in the cells across animals. There redundancy in connectivity in in in between

40:06 animals. And also there's redundancy and that is throughout different cortical areas.

40:14 you can take a plug from the lobe, temporal lobe, frontal lobe

40:20 you will find similar circuits and you find these parameter cells in there as

40:26 . Give Me 1 2nd Place. . Neocortex. New cortex is both

40:38 layered structure and a column of It's found only in mammals. And

40:46 really a structure that organizes all of neuronal inputs and outputs and dictates the

40:57 . The structure dictates the function and function can affect the structure also.

41:02 are synonymous. If you were to neocortex and you were to take it

41:07 occipital temporal loan rat or human you would see a strip layered structure

41:18 so you can see this is a stain and you can very clearly see

41:22 denser bands of cells here and these bands of south means that there are

41:29 packing of the neuronal settlements. But by looking at this corona section through

41:37 cerebral cortex, we can tell that clearly 123423 doesn't have much of a

41:46 boundary, therefore subdivided into abc at five and layer six. So the

41:53 superficial layers one and the deepest layer six. If you were to look

42:01 the cortex and layer structure, you say it has a laminar anatomy.

42:07 then if you were to do certain such as golgi stain or initial

42:14 you would see that these cells are communicating up and down this layered structure

42:23 referred to as a columnist structure. it has columns and this is a

42:29 stain for you which is a Weigert wider stain will specifically stain axons which

42:36 these very clear columnar like connectivity in little Patricks of the neocortex that we're

42:44 at, like I said, you take it from frontal lobe from primary

42:52 cortex in the frontal lobe from the association cortex and parietal lobe from primary

43:00 cortex in the occipital lobe and its large structure. And it's similar in

43:07 arrangement and packing density and it's a different than the overall thickness of the

43:13 york cortex. So neocortex, the letter structures called neo. Because it's

43:21 . This is the hottest latest thing the brain that has formed through

43:26 Six large structure. Remember when we at the hippocampus and we studied hippocampal

43:34 and I said there's excitatory cell that's by all of these inhibitory cells.

43:40 ? I said it's a three layer and it's referred to as our key

43:46 or archaic cortex. So hippocampus is three layer structure in this old cortex

43:54 a cortex. New cortex is six structures. New cortex evolutionarily. It's

44:00 . However, I keep saying that wants to become a cortex too.

44:06 there is, in my opinion uh something very interesting going on in hippocampus

44:12 the connectivity of hippocampus and maybe a years from now hippocampus will be a

44:19 large structure just like the neocortex And it will no longer be called

44:24 cortex, neurons form columns that have response properties within the column. These

44:39 come in different sizes from very small columns and they are like a local

44:46 network. There's many networks involved in a task with this local processing

44:53 You may have multiple columns next to other, processing the same information.

44:58 you have parallel processing or you have redundancy in processing the same information through

45:04 columns. Remember radio glial cells during early development they stretch themselves and become

45:12 a lattice on which neurons climb to their final destinations. So at the

45:20 of the micro column. During early this is a really cool thing.

45:24 gonna be one master mike radio glial that is going to regulate and allow

45:31 neurons to hang on to populate this and adjacent column is going to be

45:37 radio real master south that's going to neurons populate the micro column next to

45:43 . So there's something interesting about the glial cells and the development of these

45:49 columns is a limiting factor. After factor in the destination for neurons but

45:54 factor in the sizing of these columns they're using one lattice to climb across

46:01 one micro column and not that one over which would form the other micro

46:09 comedian. Broad hman, he stained , they studied it, he's famous

46:18 uh he devised side architect tonic Remember you said different functional areas are

46:25 by observing variations in the structure That's not enough. You have to

46:29 the structure itself, you have to the subtypes of cells, you have

46:32 know the connectivity of self, you to know the subtype and as far

46:35 exciting or inhibitory projections or non So this this is somewhat limiting but

46:41 is a huge advantage in looking at brain and organizing the brain based on

46:46 architecture. The other interesting thing is if you use nestle stain you actually

46:50 distinguish between neurons and glia. Remember stain will not reveal the processes the

46:56 anatomy of them. Rights and accents stain all of the cells but it

47:01 be used poor stand to distinguish neurons glia but it can Okay so then

47:09 have different parts of the brain that and by the way we're gonna come

47:15 and study the cortical connectivity in much detail. So this is just introduction

47:22 the sixth layer and calling the You should know these dies. But

47:28 we study the visuals system and I'm sure we're going to get to the

47:32 of the visual system in this But the second section of the course

47:36 try to study the visual system. look into exact circuit connectivity in the

47:41 york cortex. So there will be information coming about new york cortex in

47:48 brain We have areas that are called . Then we have areas that are

47:55 secondary in motor areas and association And those association areas are particularly large

48:05 complex in primate brains. So what we mean by primary area? Primary

48:13 is how much of the brain how much of the brain mass is

48:22 to receiving auditory information. That's what information is. It receives obviously through

48:28 years. But when it gets to cortex, how much of that cortex

48:33 listening, How much of that cortex looking at the stimulus, how much

48:40 that cortex is processing some out of information. So you look at the

48:49 very large part of its brain is to visual information, auditory sensory motor

48:57 then you would say wow in humans visual information and is so small.

49:02 that mean that rats have by far advanced visual system? That's not the

49:08 . It's actually just the opposite is you look at the complexity across the

49:15 here from rat to capture human what seeing in the cat. That visual

49:22 . Overall visual area in red is relatively much smaller to the rest of

49:28 size of the brain than it is rodents. And if you look in

49:34 , that visual area which is primary is even much smaller relatively to the

49:42 of the size of his right, does that mean? Primary you may

49:48 of almost like primal? Not but you can think of the primary

49:54 primal. What I see what I , what I smell what I feel

50:03 areas. Secondary areas, tertiary they're co ordinary areas. In each

50:10 the information becomes more and more There are areas in the brain that

50:17 join the information across different sensory That means that the auditor information is

50:26 meet visual information. It's gonna meet information is gonna meet emotional information is

50:33 meet number information and so on. those areas where these sensory modalities intersect

50:43 get processed in complex ways are called areas. So in these lower

50:51 animals, their primary, what I occupies a lot of their brain.

50:57 humans, it's not what I but it's how do I interpret what

51:03 see? Way more of the brain is dedicated to. How do I

51:08 this primary primal signal? How do join that visual signal with auditor's

51:17 With sensation from my body. So you can see, humans will have

51:25 primary areas and large areas of the . And be dedicated to Association

51:34 two More complex processing of the So it makes this lower or the

51:40 more simple, actually, more more area processing basic information what I

51:48 rather than how do I interpret what see? So, association areas is

51:58 the magic happens. It's where you're happens. It's where your association with

52:07 a certain color. I'm in love I hate the scholar and the

52:11 It's killing me and I hate but I love rock and roll and

52:16 of these things come together. So association areas is where the magic

52:25 . Association areas is what gives us is humans and how we perceive

52:33 We don't perceive things the same way how we interpret things but we don't

52:39 things the same way. There could something that happens factually between two people

52:45 a fact happened and those two people walk away interpreting what happened completely

52:53 And some may say this did not , it's not a fact. How

53:00 that come about? How does that about in anything in life? But

53:06 does come about in any place. you have an argument with a

53:10 No he or she didn't say She said that. No he didn't

53:13 it. You play the phone. , she she said it. So

53:18 happened to you at that time when saying you forgot it or you're interpreting

53:23 differently. So there's all of these things that come into play. But

53:28 areas is what makes us more individual think is more complex. Gives the

53:35 to interpretation. The diversity to our also motor outputs eventually their motor outputs

53:42 speak your right to draw something and or something. And at each station

53:47 primary to secondary to tertiary coronary association , the processing becomes more complex

53:59 So what you see gains a lot context and interpretation and you have parallel

54:10 . So you'll have a perfect example years, two eyes the processing

54:17 some of that information is overlapping with right ear can hear is also with

54:22 left ear Can hear Part of the visual field overlaps with the left eye

54:27 field. So you'll have these parallel streams and then on the micro scale

54:32 have smaller parallel processing streams. But each state station from the I.

54:38 primary visual cortex, secondary to the visual information gains more and more

54:45 more and more complexity until it goes association areas where now it gets

54:51 Co joined with the feeling with the , with the sound and so

54:59 There's a lot of different parts of brain here would like them all.

55:06 spinal cord which is uh missing here the very top is hidden by the

55:13 the slide, major divisions the spinal sacral, lumbar, thoracic, cervical

55:19 stem from the of long palms. midbrain here dot which is the thalamus

55:28 top, hypothalamus below. Basal ganglia an important nucleus in the brain that

55:34 involved in motor command initiation in Yeah, hemispheres here. So this

55:42 cord receives and processes sensor information from joints, muscles of limb and

55:52 Everything that your spinal cord processes is down. That means from here from

56:00 head information inside is processed by the stem and then further up by the

56:09 regions. So spinal cord fields, and spinal cord has motor neurons the

56:18 output to movement of limbs and write. The command comes from the

56:25 , left cortex move my right what would move my right arm.

56:33 for modern urz motor cortex send that to the connections to the spinal cord

56:40 spinal cord said contract this muscle this this muscle relax that I don't relax

56:46 boom. There is a command that from eventually from the modern neurons that

56:52 studied from the spinal cord but it in the cerebral cortex. Brain stem

56:59 well you have a lot of sensor from muscles of the head and

57:06 Motor control of head muscles, sensations the face and head. Brainstem also

57:14 the nuclei that regulate arousal and awareness it has cranial nerve nuclei which you

57:21 learn in this course the cranial nerves sensory and motor information and also in

57:28 brainstem. You have nuclei that are we call them special senses nuclei for

57:35 , balance and taste. Medulla oblon is vital, autonomic functions, breathing

57:42 rate, digestion. You have damaged maduro of long gotta. It can

57:47 deadly because you may lose control of breathing or the heart rate ponds is

57:53 you have a lot of the inter between cerebellum and cerebrum. And so

58:00 have a lot of motor information that crossing in between cerebrum and cerebellum,

58:07 is responsible for force and range of and learning motor skills. So sarah

58:16 is responsible for what we call procedural . Your motor skills or procedures that

58:24 do. What is an example of memory riding a bicycle, it's not

58:31 not facts, you can remember facts the bicycle but knowing that your brakes

58:36 salmon or something else is not gonna you ride the bike just helps you

58:42 . So once you learn how to the bike, do you ever forget

58:50 ? No. That's really interesting about procedural memory is that you can recall

58:56 instantly. And even if you don't a bike for 20 years you can

58:59 down, you're going to be a bit of balance while going there you

59:03 . But try to solve an equation yourself 20 years ago or even five

59:10 ago, that's really way, way more complex, right? And

59:17 not that writing a bicycle, keeping balance and watching everything around is a

59:21 task but the memory encoded for the and the cerebellum is very strong and

59:26 states and it's called procedural memory. we talked about the hippocampus, we

59:31 hippocampus is responsible for semantic memory. there are different types of memories.

59:37 of us are better at remembering facts storytelling and that's a semantic memory.

59:43 some of us had really well developed procedural aspects and very well developed serb

59:51 this muscle memory and performance that athletes do is also involving these brain

59:58 These it's not just building of a then you know, it's it's building

60:03 a muscle but you're if you're a , if you're some pole vaulter or

60:08 else, you know that's that's really and you recall it so it will

60:17 peed uncles. We look at the , we can cut off the cerebellum

60:21 attach the pause here at this particular uncles, it's just the name of

60:27 area, mid brain uh sensory and functions including eye movement and coordination of

60:38 and auditory reflexes. So that structure talked about corporate quadri gemini is responsible

60:45 visual and auditory somewhat of reflexes. you may this information from all over

60:57 nervous system and route to cortex before get into cortex to go through diet

61:02 stuff alone and before things exit out cortex to go through hypothalamus is the

61:12 of the knee thalamus that is responsible economic and voluntary bodily functions. It

61:19 it is somewhat of a neuro endocrine and it's also can influence the glands

61:32 hormones and hormone induced hormone release and functions and hypothalamus is also a part

61:41 HP. A. Access if you about it. Hypothalamic pituitary adrenal

61:52 hypothalamus to pituitary gland two adrenal is organ and kidneys. Uh So what

62:11 that HP access do? It's your axis, it's the cortisol the stress

62:17 control access. And so hypothalamus is in in the stress response and control

62:25 the H. P. A. release of the stress hormone which is

62:31 cerebral hemispheres to have cerebral cortex throughout different hemispheres. When we keep mentioning

62:37 of the nuclei in the cortex are collections of south such as basil ganglia

62:44 as hippocampus which you already know very and function of basal ganglia is coordination

62:50 initiation some of the movement patterns but informs the motor cortex that's performed this

62:59 pattern. Motor cortex says remember this ? Okay you reminded me I'm going

63:04 send the signal, this is the so it's encoded and basal ganglia will

63:11 responsible for initiating and some of these that I'm talking about for campus semantic

63:20 . Magdala is part of our emotional emotional processing. It's also a fear

63:28 linda brain. So these are some the three sort of cortical structures but

63:35 not cortex that you discuss to a or lesser detail throughout the course.

63:47 you're playing tennis and it seems like pretty simple task. But let's see

63:54 needs to happen in the brain in for you to play tennis. Tennis

64:00 flying after you. What happens? see the ball? So the first

64:07 is you see the occipital lobe gets right? You're measuring the speed of

64:12 ball with the rise pre motor How should I approach and hit this

64:20 ? The motor commands right basil gang involved too. The amygdala is also

64:28 just the motion but also part of home state is up keeping regular from

64:32 ecstatic environment. But emotion, emotion important. I want to win this

64:38 . You need to have emotion, need to have motivation to hit a

64:42 shot, right? And maybe great memory in your cerebellum and maybe even

64:55 memory, you know this is my game with this opponent. I'm on

65:00 to I have to win this, know, his name is stone,

65:03 her name. Now you're about ready hit the ball all of a sudden

65:10 parts of the brain kick in. when you're hitting the ball of course

65:15 looking but now a lot of it motor function, execution of that basil

65:22 that initiates the pattern and recall of . Motor pattern says the signal communicates

65:27 motor cortex. The command comes from cortex, hit the ball, you

65:33 hippocampus again, semantic memory is important . Remember that shot, Remember that

65:39 I had when I won that I want to have that feeling

65:43 I want to be a loser. I hit that ball point. So

65:50 is responsible for appropriate exception, which the orientation of your body with respect

65:58 gravity and the objects around you. the net tennis net and the

66:04 Okay, and how you're leaning in that's appropriate exceptions are about them.

66:10 cerebellum is fine tuning of the already motor commands. So the motor command

66:19 hit like this and you're running to the ball and the ball bounces off

66:25 little stone because you're playing on the court and instead of flying straight into

66:31 rock into the racket, it seems be turning slightly this direction. But

66:36 command pattern already initiated the front hand now is what we call the middle

66:44 steps in and says, do the and you return the shot right?

66:51 there's fine tuning and there's adjustments and lot of times cerebellum for that matter

66:56 called the middle management of the murder executions. Racquetball is a great example

67:03 I think of the cerebellum function because has uh wall surrounding it and the

67:11 can bounce and you can put a on the ball in a different way

67:15 you think the ball is going to far, but it actually stops and

67:18 or vice versa. It's bouncing off wall one direction and then something happens

67:23 the curve of the ball and then doing something else. So once the

67:29 is initiated, many adjustments can be , especially in racquetball, you have

67:34 have the brain stem, you have have arousal, you have to have

67:38 , you have to have heart you have to control it. A

67:42 of times. I'm still learning how breathe. Actually it takes a

67:46 very long time to learn how to when you talk and not to choke

67:52 because you're trying to get 15,000 words with one breath and so on or

67:58 you're working out. It's also we're you know have to control your breath

68:04 some of it is conscious and some it is just vital functions but you

68:08 influence them with what you're consciously Alright now we're gonna go into more

68:16 on the brain. Let's see how slides I can cover today. Maybe

68:23 just this slide which shows you more any one of these great exam questions

68:32 labeling. So you may want to some of these like auditor cortex.

68:39 cortex beyond just occipital lobe that you visual cortex that have auditor in the

68:45 lobe. This amount of sensory is right here and the parietal, the

68:51 area of the primary motor cortex. the frontal lobe this is referred to

68:55 pre frontal cortex. There's a gustatory cortex of some of the court assists

69:04 process certain information are not all on surface. And you have to actually

69:09 off some of these salsa and gyrate find a seat for that particular

69:16 Okay and so yeah maybe how many slides we have left? We have

69:27 Uh let's say 45 minutes left. I just like to introduce this slide

69:32 the last slide today. It's a of the thalamus and hypothalamus thalamus here

69:42 . So sub cortical. It's called cortical is below cortex. Hi is

69:49 the following. It's following this information all of the C. N.

69:54 . For a very long time. nuclei which stalinists is huge tolerance is

70:01 a collection of many different nuclei and nucleus and the following. This is

70:08 for specific information processing. So for visual information from the retina comes into

70:17 lateral gene Nicholas nucleus and from lateral of the thalamus it projects into the

70:25 visual cortex. In the occipital lobe information comes into the medial nucleus from

70:35 ears and for medial nucleus that information go into the auditory cortex. In

70:42 temporal lobe it's a matter sensor information the spinal cord will come through the

70:51 column nuclei. I don't need to that to make it smaller and larger

71:04 comes in to the ventral posterior lateral of the thalamus. So that's all

71:12 sensor information and then it goes into amount of sensory cortex. So what

71:19 stalinist stalinist is a collection of nuclei are responsible for different sensory functions that

71:27 going into the cortex and for a time it will stop the thalamus is

71:34 . It's like a relay station. carry the signal from the regiment to

71:38 thalamus. The thalamus passes it on cortex. So like it doesn't do

71:43 just it's too far from the retina the occipital lobe. Primary visual cortex

71:47 thalamus halfway through. Whoever did the . Put the eye here and put

71:53 visual cortex in the back. But think there is a reason for

71:58 Maybe more states can sometimes be You can do more complex inter inter

72:03 in between. So not passive tolerance not passive. What we've learned is

72:11 when the inputs come in from the they're adjusted in the following days when

72:15 inputs coming from the ear cochlea, adjusted in the thalamus the thalamus gates

72:21 modulates the signal flow information. It is interestingly following. This is mostly

72:28 of excitatory cells. There's some inhibitory with this excitatory cells of projection cells

72:34 L. G. M. That project onto the cortex. But the

72:39 following this has this really interesting sheet is referred to as red articular

72:47 It's a sheet that covers the whole and it's a sheet of inhibitor

72:54 Inhibit ourselves that control the activity of thalamus and activity between the thalamus and

73:01 cortex and from the cortex back into followings it's almost like a mesh like

73:09 . Very thin couple of soma Uh So much layer like structure have

73:17 following us is responsible for our dynamic under cream glands and hormones visceral

73:26 body temperature. The blood brain barrier the blood and hypothalamus is pretty

73:33 So hypothalamus sort of your gauge for going on in the blood like the

73:39 . Like some toxins even that can in your blood hypothalamus is gonna start

73:45 to uh it can influence appetite, intake, control sexual activity, lactation

73:57 slow growth as in hormone induced growth your slow growth development. And does

74:07 mean that this is the only part the brain that will regulate appetite or

74:14 activity? No but it's an important and plays a role in these complex

74:20 that we have. Super charismatic Super charismatic nucleus is Located right where

74:30 chi as um happens between the two . So were the two optic nerves

74:40 in. This is optic nerve from eye and optic nerve from that.

74:44 know we stripped off the brain so looking at the cranial nerves. And

74:48 worry we'll come back next lecture and all of the cranial nerves at least

74:53 that are important for us. So is optic nerve. One optic nerve

74:59 left right eye. The component one of the optic nerves is going to

75:05 over in the area where it crosses is known as the optic eye.

75:11 supra cat asthmatic nucleus will be located next to the chi as um.

75:20 and that's super cosmetic nucleus is the body clock regulator or regulator of the

75:31 rhythms. Those are the rhythms that diurnal rhythms. This is why we

75:37 to go to sleep at night and want to wake up sometimes in the

75:43 but light stimulates us to wake up the super asthmatic nucleus will contain certain

75:52 factors and with ambient light and then daylight coming in, they will stimulate

75:59 , light mode or daylight transcription factors molecules. And when the sun starts

76:06 and artificial lights kick in which a spectrum from the sunlight, then the

76:13 happens. This transcription factors that are night take over and they start producing

76:20 and interactions that are important for sleep your night cycle. And it's an

76:28 , very important uh nucleus. And you have traveled overseas and you know

76:37 there's this thing called jetlag, what lag means is that the jet has

76:44 from the United States, let's say . But your body is lagging,

76:51 body is still living in the United clock, Although now you're seven or

76:58 hours ahead of the clock in Or if you're in Asia 12 hours

77:04 of the clock. Right? And the larger that that separation is,

77:10 harder it is for people to So if you go, you know

77:15 Louisiana to florida, it's one hour , you don't really notice it.

77:21 you go from east coast to the coast, its three hour difference,

77:27 actually start noticing it a little But when you cross this kind of

77:33 56 hour difference and more you really noticing that your body clock is adjusted

77:41 it has a system and then for to adjust it to daylight and night

77:46 for nighttime signals takes time. And lag, you know, for experienced

77:51 is a day or two. Inexperienced a week and then you got to

77:55 home and adjust your time again to your home is at that time.

78:03 , most of the accidents that happened accidents, they typically happen at night

78:11 early, gone kind of a light . That's because third shift of the

78:18 shift is very difficult and as much you train yourself to work at night

78:22 we have a lot of industries, south of here, the energy corridor

78:28 all of the refineries, all of factories that work 24 hours. The

78:33 are very complex, but the human reacts to the environment. The circadian

78:38 is go to sleep and they're like , I'm getting paid to work at

78:41 , so I'm gonna stay awake and circadian clock wins. And humans make

78:46 mistake and you know, something an oil spill or a chemical spill

78:51 something like that. All right, end it here. And when we

78:55 back we're gonna finish talking about major , will review the cranial nerves,

79:02 spinal cord and talk a little bit imaging of the brain function. And

79:07 should conclude our C. N. . And we may start going into

79:11 visual system. Next election. Let check the chat. Okay, somebody

79:24 . Alright, everyone on zoom. see you on Wednesday. Don't stop

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