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00:02 | last lecture we started talking about the of the central nervous system and we |
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00:08 | the concept of new relation from the primordial tissues uh under Massoud ERM extra |
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00:18 | . We talked about how this neural folds and neural to formation if it |
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00:26 | that the caudal parts uh this section here the neural tubes, it can |
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00:35 | a condition that is called spina abnormal neural ation of normal folding of |
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00:44 | tube can result in a spin of if it is on the coral side |
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00:50 | in very very rare cases and stuff , which would be the rostrum part |
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00:57 | the new relation. Of course it's it's a fatal developmental condition. Again |
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01:03 | quite rare as we talked about. developmental malformations are quite rare in humans |
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01:10 | the structure is pretty complex and it about from the President cephalon. Mesen |
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01:16 | , ramblin cephalon which differentiates into brilliant into telling cephalon. Diane cephalon |
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01:23 | the vesicles and mesen cephalon, a in hind brain further differentiates and we |
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01:30 | about how from the talon stuff along uh tell anencephalic or to tell encephalitis |
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01:39 | the ride become the left and right that are interconnected with the corpus callosum |
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01:47 | diane cephalon is comprised of the thalamus hypothalamus and there is strong interconnections through |
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01:54 | internal capsule between the thalamus and cortex cortical alarming communication as well. So |
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02:02 | major parts of this brain ship, rostrum was telling cephalon dan cephalon is |
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02:07 | thalamus. It's all part of the . Mesen cephalon is the membrane Rambert |
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02:14 | , hind brain. Mesen cephalon uh differentiates into detect them and take |
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02:22 | The roman cephalon differentiates into cerebellum and and medulla oblon gata. And finally |
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02:31 | have a spinal cord. We discussed ventricular structure in the brain where you |
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02:36 | the two lateral ventricles, the third fourth ventricle and to the spinal canal |
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02:43 | the spinal cord. If we look the structure across different species and across |
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02:50 | cortical areas in those species can take little plug from the alligator brain, |
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02:55 | little plug off the rat cortex you'll similar structure and you will see similar |
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03:04 | layer structure as well. And you'll some of these similarities even in |
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03:10 | So let's talk about new york cortex cortical organization overall and how we basically |
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03:19 | the cells. Okay, so as recall we had two types of stain |
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03:25 | had the golgi stain which picked up of the processes and we have the |
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03:29 | stain which steam for all of the . It was really good for cider |
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03:34 | studies and so in the cortical organization you have in the cortex you have |
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03:42 | layers structure. Okay. And if recall uh part of me, I |
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03:48 | know where this keep sliding and control finger in the cortical organization. Which |
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03:54 | cortex is found in mammals only. really organization of inputs and outputs the |
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04:02 | is all of the sensor information and of the internal information from in between |
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04:07 | circuits that is being processed and the . Ultimate output is the motor command |
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04:18 | you're speaking and you have to move tongue or you're moving or you're running |
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04:25 | you're picking up a pen or your . So this is the outfit. |
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04:31 | all of the structure depends on function function depends on structure. So the |
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04:38 | are inevitably intertwined neocortex means that its cortex so this still in self alone |
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04:49 | different parts to in the cerebral But the top part of it is |
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04:55 | neocortex is the sixth largest structure and neurons that are organized into columns and |
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05:07 | . And what I mean by that if you look in the frontal parietal |
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05:14 | temporal lobes you will have six layers are prominent layers and you can reveal |
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05:19 | layers using the missile stain. So you have 1234 A. B. |
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05:26 | 56 layers. And you can see certain layers will contain densely more densely |
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05:34 | cells. And this is reflected by more of this blue stain where each |
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05:40 | of this punk tape, blue punk represents a cell. Now these cells |
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05:46 | the layers if you stain up with stain will reveal to you that a |
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05:52 | of the pyramidal cells let's say located in layer five there's so much located |
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05:58 | lower five project they're dumb brides into ethical regions to they're one and the |
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06:06 | down their eyes that radiate out in five. Use the missile stain again |
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06:13 | will show you all of the And what's interesting is another stain is |
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06:19 | stain. This is a new stain this stain is specific to axons. |
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06:25 | if you use Weigert stain very quickly realize that there is there are these |
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06:31 | are like if the layers are horizontal the neocortex then these columns. |
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06:40 | These connections here revealed with wider stain that there is a vertical communication from |
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06:49 | five or lay one or five or so whatever. So you have columnar |
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06:57 | laminar structure that laminate for layers and for columns, columns. Essentially our |
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07:06 | packed with neurons that process similar information have similar response properties such as visual |
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07:16 | that are packed in the column will responsible for similar response properties in the |
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07:23 | cortical area. And some of these are micro columns which means that they're |
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07:28 | small and other columns are larger and called hyper columns. And we'll learn |
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07:34 | that when we study the visual system we learn even more about this |
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07:39 | Call a circuit. But this is really good introduction to this. So |
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07:47 | local processing that happens. It's like local processing network in this. In |
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07:52 | column. The cells will be processing type of information. There may be |
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07:59 | columns located next to each other that be containing south of process the same |
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08:05 | of information or very similar type of . So you have parallel processing taking |
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08:10 | in these columns and these columns are laterally. So this lateral connections and |
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08:18 | laminar organization allow for local processing within columns and then the lateral connections allow |
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08:28 | wide and far reaching accidents and outputs to other columns and other court access |
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08:39 | the depending on what the sensory paradigm paradigm is or what demands attention at |
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08:48 | time. Visual information versus uh versus information and so on. So this |
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08:56 | back if you remember to the santa methods of comedian Rodman Dr Rodman that |
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09:04 | labeled all of these different areas in brain using missile state and it's very |
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09:12 | that you have to use a combination these stains three or four, sometimes |
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09:16 | or six. If you want to all of the cells. If you |
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09:21 | to know subset of cells and all their processes like gold G. If |
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09:26 | want to see where they project their . If you want to know if |
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09:31 | are excited to inhibit their you may to stand for program or synthesizing or |
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09:36 | enzyme. All right. So with help of all of these stains and |
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09:43 | reveal a lot of interesting architecture in brain and uh another interesting piece of |
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09:52 | is that neocortex is a structure. so much trouble with this person |
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09:59 | Neocortex is a structure that is the structures that it's the new cortex. |
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10:18 | . And other structures in the brain evolutionarily older. So we discussed because |
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10:25 | stem, we talked about how brain has certain and is responsible for certain |
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10:32 | body functions, right? We talked how brain stem will contain nuclei that |
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10:42 | these means and producer means so without means. You know, there's obviously |
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10:48 | evolution. Very important. Brain stem breathing hard trade. So without brain |
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10:58 | or originally as a primordial human you were able to survive with brain |
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11:03 | . Later these other structures telling. phallic structures developed more where you have |
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11:09 | formation of the neocortex. The other thing in the evolution. And as |
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11:16 | look at the different species from the order species, from rodents shown here |
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11:24 | the right bottom to humans on the and cats in the middle here and |
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11:36 | are several interesting features that are outlined , primary secondary motor and association |
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11:45 | And what does this mean? What these colors mean? This means that |
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11:50 | you looked at in a rodent if you look at a rat brain |
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11:56 | you said, I want to know much of the rats brain is dedicated |
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12:02 | processing primary visual information, decoding something basic. Primary about the visual stimulus |
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12:13 | the visual world that you're seeing. this is the massive primary visual cortical |
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12:20 | , massive auditory, the massive sensor . That means that this much of |
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12:28 | brain, most of the rodent's brain dedicated to primary sensor information processing. |
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12:36 | is secondary and what is association Well, let's first look at these |
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12:43 | areas in the same color here and for visual information, auditory and sensory |
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12:50 | in cats. And And humorous. what is in stark differences that these |
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12:59 | ? Primary information processing areas in relatively to the rest of the size |
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13:07 | the brain are very small and the you go in species, the more |
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13:16 | the brain is dedicated to primary or , almost sensor information processing. Secondary |
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13:26 | processing in the brain is more This primary visual cortical area and you'll |
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13:34 | well about it later in the Primary primary uh primary auditory processing |
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13:42 | Primaries, amount of sensitive processing your what is the best analogy of what |
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13:49 | primary, what is secondary? There's tertiary areas, there's co ordinary and |
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13:54 | areas and finally there's even association So what are these different things? |
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14:02 | what is the best analogy? So best analogy is primary visual cortex. |
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14:11 | give you a rough sketch in an of the visual world in the back |
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14:17 | the occipital lobe. So take away of the features like death. Like |
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14:25 | of the other features. Just a sketch of this room. Imagine a |
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14:29 | sketch of this room. Yes. by the time you get to the |
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14:36 | co ordinary, sometimes even Penton, visual information processing areas, you see |
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14:46 | information with death perception, with all the movement, with everything else. |
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14:52 | ? So now you have a complete information. But is this visual information |
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14:57 | the absence of other senses? Like , smell, hearing? No. |
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15:06 | association areas in the brain are the where all of the information for visual |
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15:16 | , the confluence together it's areas where modalities sensory, visual auditory, emotional |
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15:27 | come together coalesce in these association And most of the neocortex in the |
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15:37 | brain says dedicated to the association That's where the complex stopped processing the |
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15:48 | , the ability to process visual while listening to something and moving your body |
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15:53 | maybe excited about meeting somebody. It comes together in these association areas to |
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15:59 | how you what your output is, output, lingo output. Uh And |
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16:11 | association areas is where the magic happens the brain, where the senses come |
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16:20 | . And as you can see the developed the brains are, the less |
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16:32 | is dedicated to primary sensory processing. more space is dedicated to secondary tertiary |
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16:39 | association areas. When you're talking about this primal sketch and then tertiary or |
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16:48 | you have a complete visual, it's hierarchical processing. There's a view if |
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16:56 | took a view from the retina and it to the computer, what can |
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17:01 | see, you would see these blotches color and that's about it. So |
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17:09 | very simple by the time it gets the cortex, you're already seeing the |
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17:15 | . By the time it gets to association areas, it's the whole |
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17:19 | you will bless other senses blended together your thoughts internally blended together with an |
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17:28 | . A lot of times you have processing in the brain that we talked |
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17:33 | . The best example is you have and right. I it's in a |
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17:38 | parallel processing. And if you take eye out, you don't lose half |
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17:42 | the field is you actually you only the periphery on one side. And |
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17:48 | significant because there is a significant overlap cross over the fibers that you want |
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17:53 | individual system. Mhm. All So these are the major parts of |
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17:58 | central nervous system. Once it you have the spinal cord which has |
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18:03 | own divisions. Yes, Yeah, . The surface area. Okay. |
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18:13 | your profit? They uh well, course they have been decided divine, |
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18:22 | by the experiments of what the neurons capable of doing. Yes. |
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18:29 | Oh, the boundaries are partly based the site, to architectural methods and |
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18:36 | stands and the connectivity that you're And so if you put all of |
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18:41 | things together, your question is If you put the if you put |
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18:46 | structure and then you poke around with lectures and you get the function because |
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18:52 | can you can put an electorate in back of the rodent's brain. You |
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18:58 | , it's more difficult with humans. a lot of these studies were done |
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19:03 | . But just to describe in a way you put an electrode rodent's brain |
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19:08 | you show the visual stimulus and then move it quite far away and you |
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19:12 | the visual stimulus and it's still only of doing a certain thing and reacting |
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19:17 | certain way. Then you look at stain with the 34 states and you're |
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19:22 | , Okay, these must be the now where exactly the boundaries are for |
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19:26 | association areas. That's a more difficult way to define it because I would |
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19:36 | as a neuroscientist is trying to understand brain for about 25 years. I |
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19:42 | say that probably there is no clear . When you're talking about association and |
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19:47 | of information that combines multiple modalities, there. But can you put a |
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19:52 | around it and say that this is ? It's it's more difficult but with |
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19:58 | and secondary and tertiary and you will beautiful anatomy and this amount of sensory |
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20:04 | over rodent that we'll talk about barrel if you're not familiar with it, |
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20:09 | that is there. You know, uh it's uh it all comes |
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20:15 | you all have to have the the structure and the function together. |
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20:20 | you're combining the dice functional studies, imaging and you can do that obviously |
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20:29 | humans in vivo non invasively to will you determine these boundaries and what certain |
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20:36 | are responsive to. It's a very question. Spinal cord is divided into |
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20:44 | own regions, is divided into the region which is cervical into the store |
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20:50 | region which is Jurassic into the lower back, lumberjack and sacral which |
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20:59 | in your um tailbone essentially spinal cord and processes sensor information as you know |
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21:08 | it receives and processes that sensor information . We're getting in south from skin |
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21:13 | , muscles of the London trunk. controls through motor neurons, controls movement |
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21:20 | limbs and trump brain stem is where of the sensor information which is comprised |
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21:26 | maduro blow. God upon some midbrain information from muscles of the head, |
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21:34 | control of head muscles. So you learn that there are cranial nerves today |
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21:38 | control a lot of the activity. everything from MAC, down movement of |
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21:43 | arms and feelings and everything is spinal from next up, you're talking about |
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21:50 | nerves that innovate the upper regions of , of the cranium Brainstem regulates levels |
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21:57 | arousal and awareness contains 12 panel nuclei are sensory motor. Some are responsible |
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22:05 | both and can process special censuses involved hearing information, balance information and taste |
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22:15 | processing at the level of the brain . So that's that's pretty cool. |
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22:21 | is certain amount of information processing at level of the brain stem. Think |
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22:26 | evolution, you heard something, your stuff could have processed a little rudimentary |
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22:33 | in there. So we'll learn maybe . When you study the systems more |
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22:38 | you learn what that's something they have . Wait medulla oblon gata, his |
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22:46 | economic functions, breathing heart trade a bit digestive functions, calls right |
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22:56 | They have these uh pete uncles that to sort of balance and a lot |
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23:03 | uh motor information from cerebellum hemispheres. also have left cerebellum, right cerebellum |
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23:13 | to cerebral hemispheres, information from cerebral too cerebral and vice versa from cerebral |
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23:23 | to cerebellum. The belem is for range of movement. That's what it |
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23:31 | and remember that it controls it. laterally as opposed to neo cortex of |
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23:36 | cortex will put the command from the of the right side of the |
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23:41 | What cerebellum all you're right cerebellum will the right side of the body force |
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23:50 | range of movement, learning motor It's responsible for what we call a |
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24:01 | that is procedural member, you know types of memories, semantic memory is |
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24:09 | telling you a story and how you a story, semantic memory events, |
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24:16 | , people names, procedural memory is you ride a bike, how you |
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24:26 | serf. Yes. Are you How do you jump hurdles? And |
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24:36 | is where the range and management of movement and fine tuning of the movement |
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24:43 | motor commands that get initiated at the of the cortex and get adjusted fine |
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24:50 | by the cerebellum. Uh And what's about procedural memories is that they cannot |
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25:00 | erased unless there is a trauma or of the cerebellum. In other words |
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25:10 | may forget, would you study in course after you take the test? |
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25:19 | not. That's why I repeat things lot of times. Uh But you'll |
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25:24 | forget how to drive a car, never forget how to ride a bike |
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25:30 | if you haven't ridden a bike for years. Okay. You may fall |
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25:36 | it will take your circuits maybe to with the balance. But it's not |
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25:41 | you don't know how to ride a . Maybe you just haven't been in |
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25:46 | kind of a appropriate sector uh motion environment. So it's very deeply |
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25:55 | Pete Danko says what will connect To brainstem and that's where a lot of |
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26:01 | , serverless cerebral cerebral, sorry Bella or so located midbrain a sensor and |
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26:08 | functions including eye movement as well as of visual and auditory reflexes. So |
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26:16 | what we're talking about. Special census . That's pretty cool. Visual and |
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26:21 | reflexes. The brain stem. Again you think about evolution has some |
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26:26 | Visual and auditory processing die and suffer thomas and the hypothalamus and we'll look |
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26:39 | the following slides that show it all of the information from all over |
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26:47 | . N. S. And round cortex goes through thalamus all of the |
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26:54 | all of this is not a sensory information from the retina goes to the |
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27:00 | before it goes into cortex. And has these massive paloma cortical connections from |
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27:06 | to the cortex. And cortical thalamic from cortex back into palamos. Hypothalamus |
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27:13 | below is involved more in the Gnomic in control of voluntary bodily functions |
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27:22 | well as and Ukraine and visceral And hypothalamus is really a part of |
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27:31 | endocrine system. Yeah. You ever of the H. P. A |
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27:41 | ? You haven't don't worry about it it's a very important access to controls |
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27:51 | release stress hormone release and therefore uh a way hypothalamus has a whole para |
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28:05 | attacked on the human body. It serves as a gauge of the blood |
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28:13 | it has very thin blood brain So it can detect some toxic molecules |
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28:19 | to end up in the blog and detect changes in temperature. So it's |
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28:26 | in thermal regulation hypothalamic pituitary adrenal That's what HP. A. Access |
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28:40 | for. Uh pituitary. There's a gland. The cns actually talk about |
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28:49 | again in the visual system. I . No is a Drina Drina |
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29:03 | So you have this control of cortisol the system. And hypothalamus is involved |
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29:09 | much so. And that regulation of induced hormone release cerebral hemisphere cerebral cortex |
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29:18 | cortex major nuclei that serves some very functions basil ganglia which has a lot |
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29:25 | the initiation and storage at least motor , complex motor commands, uh non |
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29:35 | commands and motor patterns in the way which you know from the circuit perspective |
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29:42 | hippocampus has all of these different subtypes inhibitory cells and excitatory cells. From |
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29:48 | functional perspective hippocampus is responsible for learning memory, right? For encoding memory |
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29:59 | also for retrieving memory. The hippocampus not store memory and memory. Different |
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30:06 | of memories are actually widely distributed throughout brain to retrieve them. You may |
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30:13 | to engage the hippocampal circuits again kind go back into the box here and |
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30:17 | some member and drag it out through . It's also and influenced and is |
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30:24 | in emotional information processing. But the , the hippocampus is responsible for a |
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30:30 | memory, both short term memory and term members. The the encoding of |
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30:38 | memory and retrieval of that memory. is another very important structure in the |
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30:46 | that's involved with emotional response as Reading emotions, understanding emotions and other |
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31:00 | from other faces. As long even behaviors. Use many parts of the |
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31:06 | . So what is a simple Oh just throw a ball and hit |
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31:09 | ball when you think about it Now start understanding if there's a player and |
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31:15 | player is looking at the ball. means it's visual cortex is engaged and |
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31:21 | anticipating something. So the visual cortex watching the ball, the pre motor |
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31:27 | is concerned with, how am I to basically get ready and hit this |
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31:32 | back. So it's already starting to engaged, What's gonna be the motor |
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31:37 | ? You have other areas of the , you know, like a |
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31:41 | It's from your synthesis emotional processing, motivation to hit a good shot, |
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31:52 | cerebellum is adjusting fine movement and the way to think about the fine movement |
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31:59 | maybe not tennis because in tennis you the ball flying and you have enough |
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32:03 | to prepare and hit it back. racquetball, if you ever played |
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32:09 | the element of surprise and racquetball is walls, there's no walls in |
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32:15 | So when somebody hits the ball to to and it hits the wall, |
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32:22 | can also have a spin. And spin can make the ball fly either |
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32:26 | direction or stick closer to the So now was you prepared to hit |
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32:34 | ball? The spin all of a is flying over here and now you |
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32:40 | to fine tune that motor command that originated from basal ganglia, but you |
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32:45 | have enough time. So then it fine tuned through serb alums middle management |
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32:51 | and let's say instead of hitting this forum will turn around, it's not |
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32:57 | the back are so motor pattern initiation on and the basil ganglia, you |
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33:07 | uh appropriate exception. Also that's coming cerebellum. Where is my body |
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33:14 | in in in location to the ground location to the net in location to |
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33:23 | lime. Remember on how it hit game points ball. And thats hippocampal |
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33:34 | telling you remember that that's part of semantic memory, how and you know |
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33:38 | open 2019 I won this and it's of the whole game to motivation. |
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33:46 | the behavior is initiated, you can it with the cerebellum. Of course |
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33:52 | talking about brainstem, you're talking about body functions and keeping your heart rate |
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33:57 | , respiration. Uh And it all to be in check because there's quite |
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34:04 | lot of excitement. People that are the on the field for decades. |
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34:12 | they still run out on the NBA after playing for 10 years. And |
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34:18 | still that initial frighten anxiety and excitement you know, 20,000 people screaming at |
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34:26 | good or bad and uh all of is a part of it. So |
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34:32 | also have the ability to filter out focus on certain things to. |
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34:38 | Mhm. So when we look at neocortex again, these are all of |
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34:46 | familiar areas for us. Prefrontal this is pre motor area and this |
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34:53 | primary motor cortex area for this is somatosensory cortex, on the parietal of |
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35:03 | , this is the visual cortex area 18, 19 of the primary visual |
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35:08 | . This is the auditory cortex Areas 41 42 is the primary auditory |
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35:16 | areas. Uh There is a gustatory uh for sense of taste in there |
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35:28 | . Diane cephalon nous allons information from over cns and route to cortex for |
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35:34 | long time it was thought to be a relay station for information from the |
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35:41 | from all of the sensory organs coming Fallon was before they go into the |
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35:46 | . Again, cortex is hierarchically most , most advanced structure. So that's |
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35:52 | you will get the complete absence of . And so the cells in the |
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35:57 | are called relay cells really neurons are to re really neurons. And for |
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36:02 | long time thomas was viewed as oh a relay station. So it's just |
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36:09 | passive real. A there was a thomas is located all the way |
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36:15 | There was a need for let's say information coming from the high to stop |
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36:20 | the thalamus to relay that information to neuron that will carry that information to |
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36:26 | exhibit alone where the visual processing takes . So at first it was believed |
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36:33 | be real. A and then passive whatever reading the seas let's say is |
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36:41 | to the thalamus thalamus relays that information the cortex. Original view. But |
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36:47 | fact Alamos is responsible for gating. modulation of the signal gating can allow |
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36:55 | signal to pass through and not the in a way. Okay. Can |
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37:01 | modulate or can control the amount of that is dedicated to certain signal. |
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37:14 | contains a particular formation. So what is thomas is a collection of a |
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37:21 | bunch of the nuclei nuclear process, type of information. So all of |
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37:28 | visual information will go through lateral gene nucleus. It's lateral and the balance |
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37:36 | you'll find it laterally and it's a actually that's what it's called. Gene |
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37:40 | , genius corny for bump. Nicollet nucleus install all of the |
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37:46 | Visual information from retina will go into L G. M la roja nikola |
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37:50 | and then from there it will go the primary visual cortex. All of |
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37:56 | amount of sensor information will go through column, nuclear dorsal root ganglion cells |
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38:03 | put it into the dorsal column In the spinal cord it will project |
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38:07 | in the thalamus it will go into ventral posterior lateral nucleus. So all |
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38:17 | this amount of sense of information is to pass through the vpl and routes |
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38:23 | the somatosensory cortex auditor information. All the auditor information is going to go |
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38:30 | medial nucleus nucleus and that is going go to the primary auditor. You |
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38:36 | the gist of each one of these is dedicated to specific sense of information |
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38:43 | and connects that sense of information How much of it comes in modulates |
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38:48 | . You can see turns up the up and down and starting to censor |
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38:53 | projects that into the into the cortex on top of that the cells that |
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38:58 | really cells of these nuclear excited to . But on top uh this structure |
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39:04 | top of these nuclear you have a of cells that is referred to as |
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39:10 | particular formation or nucleus ridiculous Aris the nucleus. And this particular nucleus is |
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39:20 | of a sheet of the inhibitory styles . So there's local interconnections between the |
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39:28 | formation and excitatory cells. There's local of what is happening in the thalamus |
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39:35 | well as the interconnections between the thalamus cortex and the cortex back to the |
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39:40 | . The cortical thalamic and Philomel. where it originates is the first |
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39:46 | It's a llama particle. That means fibers originated. Selma's send axons from |
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39:53 | into cortex. Hypothalamus Alabama can voluntary the cream glands and hormones have already |
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40:01 | about it. And the hypothalamus is underneath the columns. This is not |
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40:05 | best picture. But we'll have a picture. I also bought a |
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40:10 | appetite, water and take sexual activity of it lactation. Slow growth, |
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40:16 | growth for hormonal release like growing growth growing slowly from being a baby into |
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40:25 | ft whatever seven super charismatic nucleus which a part of the diane cephalon and |
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40:32 | sitting there, it's a circadian rhythm . So it's a master body clock |
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40:37 | responsible for controlling the diurnal rhythm. has transcription factors that influence you sleep |
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40:44 | the evening mass transcription factors that influence levels of activity and stimulate them during |
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40:50 | daylight hours. Okay, super charismatic , it's just sky as um it's |
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40:57 | optic eye ASM and it's related to . This is another good view and |
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41:03 | are all great exam question. So can point out these structures for |
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41:07 | but you should know them by cerebellum, the visual cortex, this |
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41:13 | the corpus callosum, this is mid view. That is a good exam |
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41:19 | . Right, which plane was this made of corona, horizontal amidst natural |
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41:24 | is mid sagittal view. You're seeing spinal cord, brain stem ponds. |
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41:32 | , diane cephalon, You can see factory involves sticking out here. This |
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41:37 | a singular gyrus shown in blue some these structures we will not have time |
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41:43 | discuss, but I think you should almost everything that is on these diagrams |
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41:49 | 95% because we actually talk about 95 even more that is on here. |
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41:56 | is located here and this is the right here, shown in blue embedded |
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42:03 | three dimensions. So if a campus humans comes underneath in the temporal lobe |
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42:09 | like that and in rodents it goes to the temporal uh loading up with |
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42:17 | private lobes. Those structures are resemblance a similar but also have their own |
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42:25 | in different species of animals. Four , sarah Palin has the left cerebellum |
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42:34 | and the right cerebral hemisphere and in middle it has what is called the |
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42:40 | . And so if you were to and cut off the cerebellum which you |
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42:45 | expose as you would expose. The peed uncles. This is where all |
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42:50 | these fibers from cerebellum into the cortex from cortex to cerebellum Iran. And |
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42:56 | on the back you would expose. now you're looking from the dorsal |
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43:01 | Okay this is a dorsal view. think you're looking from the back. |
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43:05 | removed the cerebellum and now you're looking here. It was here. The |
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43:12 | body here. Okay. And a famous structure that you're gonna know. |
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43:18 | well I'm gonna ask about it almost re exam oil the corporate quadra gemini |
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43:26 | it's very important for what we study like languages. Corporate quadra gemini |
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43:36 | The body Wandera four gemini of Okay, this is the fourth structured |
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43:47 | , essentially the two top structures of left and right, superior curricula. |
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43:53 | when we talked about reflexive visual information . It goes through superior calculus, |
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43:59 | of the fibers from the retina and going through the superior calculus. We're |
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44:05 | ridiculous left and right where the auditor is going to be processed in the |
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44:11 | . So most of it is reflective the level of the brain stem while |
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44:16 | there is from auditor information for mediagenic inferior calculus it will go into the |
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44:24 | list. Mediagenic Hewlett nucleus. They into the primary auditory cortex. |
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44:31 | 12 Cranial nerves. And why do learn them in this course? Because |
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44:39 | gonna thank me for it. And we're gonna talk about few of them |
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44:47 | we already discussed. A few of are quite a great detail. So |
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44:52 | want you to know this. I you to know that this is obviously |
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44:58 | side view of the brain And that have 12 nerves that are in the |
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45:07 | . Stop. These nerves will now controlling a lot of things that are |
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45:12 | in your mouth and your face and head. Yeah. So the first |
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45:20 | is the of factory nerves which is shown on here. The second nervous |
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45:30 | the optical optic nerve is shown And this is the front view showing |
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45:37 | left and right optic nerve part of left and right optic nerve. Cross |
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45:45 | , thrown off the sky as um super. Cosmetic nucleus the nucleus is |
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45:51 | very close to the optic eye. and afterwards these become optic tracks. |
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45:58 | these optic tracts are going to run the lateral gene, Nicollet nucleus of |
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46:04 | thalamus and then into the primary visual . Mm three. Ocular Motor |
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46:16 | What do you think that nerve The next thing is that a lot |
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46:20 | cranial nerves if you remember or know they're supposed to do or what structure |
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46:25 | related to optical is optical ocular motor still something to do with vision, |
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46:33 | motor movement. Great movement of the , our killer motor. And you |
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46:40 | at truck, me and her We're now going to study its |
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46:45 | So I'm going to skip certain functions the cranial arms because they're not important |
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46:51 | what we're going to review or they're making a point that I want you |
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46:55 | remember. Number five nerve. You know because it's trigeminal nerve. It's |
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47:02 | largest nerve stock right here. That out of the brain stem at the |
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47:08 | of the ponds and it will have major fiber bundles making it trigeminal trigeminal |
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47:17 | is incredibly important for controlling facial movement of facial muscles. Found speaking |
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47:27 | so on facial expressions. So trigeminal you should know. Okay. Number |
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47:35 | is abdu since Number seven is facial intermediary nerves. Number eight you should |
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47:47 | because it's vestibular cochlear nerve. And we come to study the auditory |
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47:53 | vestibular cochlear man has two components of balance and the cochlea. From the |
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48:00 | leah here in component Glass of for is # nine. Glass of for |
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48:10 | we'll also Gloucestershire, differential pharynx, tongue, ferries, tongue, pharynx |
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48:22 | all of the your anatomy in medical . All of these latin words. |
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48:29 | them up remember. It's a code , lateral gen equivalent. You already |
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48:38 | what's media, what's lateral was gen . Okay, so the stimulus. |
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48:45 | it's not one word. What is while it's a vestibule for waiting or |
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48:51 | apparatus Biology vestibular cochlear cochlear to take words apart. Glass of for |
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48:59 | Uh huh. You should know vagus because you know it already it runs |
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49:06 | extensively and elevates the heart throughout the to this certain organs. Okay, |
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49:20 | now we're up to town. Number is accessory nerve right here. That |
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49:36 | not very important for us to We're not making a big point of |
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49:42 | . But I will make a point high gloss on our number 12 because |
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49:46 | just told you that glass Eliza So hypo what do you think this |
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49:54 | above the time or below the tunnel the town. So it's controlled with |
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50:01 | . So now what is it? are these nerves concerned with? Are |
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50:06 | sensory by the motor? Are they ocular motor? That's pretty clear. |
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50:13 | a modern nerve is gonna move the . What about the others? And |
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50:17 | do you learn this kind of Mm hmm. Yeah. I'm trying |
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50:41 | find the right slide. So how you remember the crane owners And why |
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50:49 | you want to learn? Because if go to medical school you're gonna have |
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50:52 | learn that you have to gonna have label them. And I went to |
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50:59 | in michigan and we had a human as undergraduates. And our practical lab |
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51:07 | of your anatomy and head and neck actually to label and identify these cranial |
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51:13 | and human cadaver. So it's much difficult with what I had to |
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51:18 | And so you should really try to is if you go to dental school |
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51:22 | going to have to know these, to graduate school. Anything to do |
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51:25 | neuroscience, you probably should know these unless you're just going to live in |
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51:29 | cell and one molecule for a few which happens. So uh how do |
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51:36 | remember these things? There is many pneumonic for remembering these things. So |
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51:42 | was a dark and stormy cold evening michigan 1993. It's true and it |
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51:57 | late and we had a study group we said how do you remember all |
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52:00 | these things? And we came up a pneumonic, Bugs bunny says or |
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52:06 | somebody copied it from somebody. But didn't really have access to internet that |
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52:11 | at that time. There were We have pop three email accounts I |
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52:17 | something like that. But so the was the following. Bugs bunny |
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52:24 | oh oh to touch and feel very vegetables are So okay you can make |
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52:38 | own. But since 1993 yeah I remember and I can close my |
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52:43 | I can still recall all the cranial . So oh it stands, each |
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52:51 | represents number one, oh there's no number two oh optic number three oh |
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52:58 | ocular motor Uh two T. is clear touch tease trigeminal and six. |
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53:08 | nuisance feel salmon facial. Very vestibular cochlear to green glass of original |
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53:19 | vegetables. 10 accessory 11. Uh . Hi Gloss of 12. So |
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53:29 | we have to come up with another that said which one of these nerves |
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53:35 | ? Which one is motive? So come on. It was Bugs bunny |
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53:41 | so, so much money. But brother says, bugs bunny makes more |
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53:51 | in this case the first letter. . Of the word for em or |
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53:59 | . If it's s it's a sensory . If it's m it's a motor |
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54:06 | and you can help yourself by remembering or because three is a motor and |
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54:13 | ocular motor nerve. So if you three is motor and you had a |
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54:18 | in the exam between two and one them was not. Do you remember |
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54:22 | ocular motor? You would get that . So B. Stands for |
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54:27 | That means the nerves are capable of . The sensory information and the modern |
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54:33 | . So, so so much So number one sensory or factory to |
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54:40 | sensory No three. Ocular Motors. Nerves. Number five which is |
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54:47 | These are the important ones are going now or both. Okay, number |
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54:54 | which is the stimulus. Coakley a nerve number 10. Which is |
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55:02 | It's both. Yeah, censoring Very, very cool. So now |
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55:13 | know the cranial nerves. And once the important ones, you should know |
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55:19 | one of factory because it's easy. if you remember number one of factory |
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55:24 | you'll remember the two is optic. smell one eyes too moving eyes. |
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55:31 | ocular motor five try germinal eight. to be with cochlear 10 Vegas. |
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55:42 | no these that I just named know their sensory and motor of both and |
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55:48 | gonna be all set for the exam . Okay. And this pdf is |
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55:55 | your lecture notes. So you'll find in your lecture notes, The |
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56:08 | Okay so Spinal Cord, an overview the divisions of the spinal cord 1st |
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56:19 | nerve. And you have cervical vertebrae . one And seven cervical seventh cervical |
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56:30 | and right below it you have the cervical nerve. So you have the |
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56:36 | cervical vertebra and you have eight cervical as their neck. So when people |
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56:45 | I had a surgery in C. Or something is in c. |
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56:51 | Or a disc slip in L. . So C. Is cervical |
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56:57 | Would be lumber T. Of course thoracic. And you have T. |
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57:02 | through T. 12 thoracic vertebra and thoracic nerves Number one through 5 for |
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57:09 | back and lumberjack. And then you sacral vertebra and sacral nerve here coming |
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57:15 | here. Another thing to notice about cord. Is that spinal cord proper |
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57:21 | one continuous structure like sort of a continuous cord stops at about L. |
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57:30 | L. Three. Then from there it becomes what is called cardiac |
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57:36 | So the fibers actually no longer enclosed one structure. Would rather spread out |
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57:42 | card it's called it tail A quien tale called oh you see it's the |
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57:50 | language called a nucleus Cardell. In the back versus raw stroll. |
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57:58 | . Uh Called a queen, a , equestrian horses scale. So the |
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58:05 | look like loose fibers like horse's tail enter the lower structures and the the |
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58:15 | uh and the legs. And you know this that the information that comes |
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58:22 | the spinal cord goes through the dorsal ganglion. That's where the, so |
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58:27 | of the DRG cells are located. project into the spinal cord. And |
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58:33 | a lot of the sensor information will carried through these dorsal columns. |
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58:40 | so this information is going to ascend the spinal cord into the cortex. |
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58:45 | talked about reflex artists. That happened the level of the cortex. But |
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58:51 | of the information sensor information was also the level of the spinal cord. |
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58:56 | all of the information from the spinal is also sent up into the |
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59:01 | So you have this lateral dorsal column you can see that the spinal cord |
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59:07 | the shape. Sometimes it's referred to a butterfly. Other times they're called |
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59:13 | . It has dorsal horns to dorsal and then it has ventral horns dorsal |
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59:20 | is where the fibers and DRG south command you. And you'll have some |
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59:25 | much here of the inter neurons and neurons. And then ventral horns is |
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59:29 | the motor neurons and their outfits will out through the ventral side. And |
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59:36 | three men in jeans, the S. A. Barack annoyed. |
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59:40 | the dura mater that cover the spinal proper. And going back to this |
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59:47 | showing where the spinal cord proper You will see that when we discussed |
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59:53 | time, if there is an infection the brain and you need to take |
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59:57 | sample of cerebrospinal fluid, that sample cerebral spinal fluid will actually come Right |
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60:06 | L. 203. So they will a softer needle to try to drain |
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60:12 | of the fluid from the canal there that area. Okay, so we |
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60:19 | this dorsal and ventral information processing at spinal cord. As I mentioned, |
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60:26 | a lot of fiber bundles that are in the spinal cord, the major |
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60:31 | pathways the dorsal column to all of information and then all of these are |
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60:38 | motor pathways. You have the cortical rubio, spinal the jewelry, ridiculous |
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60:45 | texas, spinal pontin, ridiculous. track the stimulus, spinal track. |
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60:51 | lot of the names of these tracks again the stimulus spinal goes from the |
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60:56 | apparatus to the spinal cord. What you think? It does? The |
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61:01 | apparatus? It helps you balance and tracking the balance on how the motor |
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61:06 | move your body and the output from motor neurons into the body within that |
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61:12 | . And of course we have the peripheral nervous system, a lot of |
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61:18 | visceral ganglia. We talked about Terek nervous system, how many esoteric |
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61:25 | system is just as complex. And thing that we always want to know |
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61:33 | the brain is we want to understand function. So now you understand the |
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61:39 | structures in the brain. Okay, we talk about the visual system will |
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61:46 | back and you'll understand more details about retina and the circuit and the retina |
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61:52 | processing from thalamus into cortex. What's into cortex with types of cells are |
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61:58 | ? But this is a broad general of how from these three primordial tissues |
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62:05 | have the Folding your relation differentiation in structures and what functions these different structures |
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62:13 | in the brain including the 12th cranial . We want to always know of |
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62:22 | how to image that information in the . And so I attached a couple |
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62:31 | interesting articles for you in your lecture . So if you go to your |
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62:39 | notes you'll find a one of the that is called voltage sensitive dye |
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62:49 | Okay and there is both a sensitive pdf and there's a review that I |
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62:55 | there. Why didn't want to talk that? Because I want you to |
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62:59 | building and understanding uh how you can different activity in the brain and what |
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63:08 | the levels of this imaging. But can be accomplished in the clinic and |
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63:13 | can be accomplished in the lab in clinic. The tops of imaging that |
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63:19 | will be doing are called macroscopic And maybe Mezza skah pick imaging. |
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63:30 | imaging will give you a nice view large parts of the brain that are |
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63:36 | for visual information processing. Then you take a specific area of the brain |
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63:42 | as the one and you can start into the breakdown and may be differences |
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63:49 | activity within that specific. Not how specific area is different from the rest |
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63:53 | the brain but what are the differences different parts of this specific area that |
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63:58 | looking at then? What is a in the part of the area that |
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64:04 | can you can look at it Is it circuit centric? So can |
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64:08 | go to the circuit level using MRI pet scans? Noninvasive human imaging? |
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64:15 | it's not there yet. So all the functional imaging again. Why do |
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64:21 | want to have functional imaging? Because understand the structure. We have all |
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64:26 | these stands Missile Golgi Weigert this and know it's the chemistry. I want |
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64:33 | see the function. I want to the function not only at this macro |
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64:40 | which is under a microscope. Macroscopic . It's not a microscope again but |
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64:46 | a microscope. You're looking at large areas. I want to go down |
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64:52 | sub cellular level. I want to down to single sanat. I want |
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64:55 | engage Glutamate on one dendritic spine and want to see what activity happens in |
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65:03 | introduce, find what activity happens in cell. What does that cell communicates |
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65:08 | the rest of the network in the ? How does a larger network see |
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65:14 | communication? What does it mean for rest of the brain? So these |
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65:20 | all of the levels. And then it comes down to circuit centric cellular |
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65:25 | sub cellular, you're utilizing experimental So we already touched on some of |
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65:32 | human imaging techniques and we'll come back this in the second. We want |
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65:36 | show you a technique that is called sensitive dye imaging. Okay, and |
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65:46 | is a technique where you have a ope. This is a macroscopic ope |
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65:52 | is going to be imaging activity in part of the brain experimentally. You |
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65:59 | now do two things. There are very intriguing dyes that are called voltage |
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66:05 | dyes intriguing because they embed themselves within plasma membrane. These little squirmy warrants |
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66:13 | they have certain reflective properties depending on . So they said, resting membrane |
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66:20 | . Big blue blue and then once membrane potential across the channels protein channels |
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66:27 | the charge across a number of These squiggly warms changes the confirmation and |
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66:33 | in the membrane And instead of blowing the chemical dye molecules are not one |
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66:41 | chemical dye molecules but they changed their depending on the voltage across plasma. |
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66:47 | it? And now they glow Well now they glow red and this |
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66:52 | you a really nice view of what happening. And so everywhere you're seeing |
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66:58 | here are active cells, everywhere you're blue, there's a significant amount of |
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67:02 | addition, so now using both of dye imaging when we talked about |
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67:09 | remember in the pre synaptic synopsis, imaging of calcium, I said there |
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67:13 | specific dies for measuring levels of calcium dies from measuring levels of sodium |
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67:20 | you name it but you also want know how the membrane potential changes and |
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67:25 | want to know that actually in a cell level if you can on a |
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67:30 | level and voltage sensitive dye allows it do it almost on a single cell |
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67:36 | , Almost from a single cell But the point being is that in |
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67:40 | to achieve this. And what else you want to do to confirm that |
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67:45 | diet is actually recording the number of you want in certain an electrode as |
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67:50 | insert an electrode, you're tracking this . So one of these traces is |
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67:57 | optical change. Okay, in the . Another one of these traces is |
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68:05 | number of potential change. So attracts with these voltage sensitive dyes and that's |
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68:12 | significant and to finish in humans. we talked about early on, we'll |
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68:20 | talking is have computer tomography ct Very popular And clinic with their essentially |
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68:29 | dimensional X ray X ray is really to see gross changes in the brain |
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68:38 | between hard and soft matter and MRI. You have magnetic resonance imaging |
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68:46 | items, no X ray, you more detail. But when you talk |
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68:50 | functional imaging, you have path which positive on the mission of demography and |
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68:56 | , The brain and the cells in brain. They require a lot of |
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69:00 | . It only comprises about 3% of total body mass. It consumes over |
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69:06 | of the total energy that you're putting your mouth and skin and everything |
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69:11 | Okay, so it's a system that a lot of blood. When neurons |
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69:16 | active, they demand more blood. they demand more oxygen. So you'll |
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69:22 | increases regionally in the oxygen levels. demand more food. What is food |
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69:28 | neurons glucose. So they demand more . So here are your clues to |
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69:33 | do you track your own or Can you put the dye in the |
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69:37 | brain vote for something to die? like in that monkey experiment and put |
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69:42 | hole in the image and send them and come back an image again |
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69:47 | So you have non invasive techniques and you have to track blood. You |
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69:53 | to track oxygen. You have to glucose. These are the core things |
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69:57 | you want to track when you're tracking . The MRI. You have hydrogen |
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70:02 | one proton, high energy or low state, fluctuate the frequency at which |
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70:08 | low state pro tiles absorb energy is resonant frequency. So the frequency at |
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70:14 | it basically goes between the low and high energy states. And then in |
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70:21 | radio waves by protons and then you these magnetic coils and it's essentially electromagnetic |
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70:28 | . It gets absorbed through these coils presents a nice image of the |
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70:33 | And F. M. R. F. Stands for functional magnetic resonance |
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70:39 | . Yes. So functionally you you have an FmRI changes between oxy |
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70:51 | and the oxy hemoglobin ratio hemoglobin is molecule in the blood that carries |
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71:00 | So if you're gonna draw more activity gonna draw more oxygen. You're actually |
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71:06 | to have more deoxygenated hemoglobin then Because those neurons are going to be |
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71:14 | information and draining the oxygen. So the basis for FmRI. The basis |
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71:21 | pet is radioactivity active solution with charged is injected in the bloodstream. So |
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71:31 | is somewhat invasive. You're putting something FmRI. You're not really injecting it's |
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71:36 | contrast liquid of contrast material. But X ray with CT scans and with |
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71:44 | you're being injected a material protons bind in the mid electromagnetic radiation and what |
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71:51 | measuring through pest Kansas glucose consumption With d. oxy glucose. So |
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72:01 | You're looking at oxygen. And with you're looking at glucose consumption. |
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72:09 | going back to the same story that are the most important functional aspects in |
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72:14 | to membrane potential. But right now nothing that in humans can non invasively |
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72:21 | fluctuations and membrane potential. The slightly with TMS stimulation, strength, magnetic |
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72:29 | that you can do that but it's being worked out of these stages where |
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72:35 | may become an acceptable way in the of pinpointing information. The problem with |
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72:42 | coils that measure information as they have access information deep and accessing information deep |
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72:49 | actually blur that. And as far extracting exact information happening versus diluting it |
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72:56 | some average or an interference that's coming the structure about. So we're going |
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73:03 | end at this stage and on Wednesday watch the lecture on the retina on |
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73:09 | visual system. The first lecture and will be back here with you on |
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73:17 | . Thank you for being here. your questions for next time as I |
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73:21 | to run out. And that will your quizzes later. Today or |
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73:30 | |
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