Review Slides

you don't get to, you can do small groups, mainstake, and remember that you test our Friday that you have a home you at the center which you checked the windows and have other reservation part take test in. So I'm gonna go basically from the independ review material fromits to on, 300 of two quest, two, before, but I also have to your questions after earlier your stuff.. especially the So when we talked to Shawn about social domestic currents versus I potentials, um and how they makes sense to try to them and organizing information in terms of comparisons, he find high, uh, so when the orig would the the post connective membranees, somewhere in the, right for for a postnetic current. and that would be ESP or an IPSP, ZS E, C zero.. Um, which is basically related in some sort of, uh modated or simpleated otherwise a, umannels that may be a receptor, a tion tennel that's called multar receptor. 
Um, there is an action potential, we talked about. It's most likely to start the, but it can theoretically start earlier and there are some cell type sphere, you does startier, as a level of deathrites, um and simply that's because um in those cells, you have enough solute channels to to really get the extra potential going earlier than any typical, um, there are the size for mostly empty currents is grad, and so they can vary inside, and we depend on hower trans nurse have activated receptors over the voice 70s memory ens of these, um, channels, where I highones, um, where is predict potential we talked by size is all the same, all gone, but it is going to that this is means that it's consistent in the size where people neuron, right? But it's for neurons the neuron, the actual actionual signature is the abstitude of the action and what is going very depending on a lot of factors. 
Um we include just the DC, uh, uh I actually was the activity of the sole of potassium from, uh with the high requires andels the resolved et cetera. up window of origin size. and then we talked about what, uh, determines how the current decies in size as it's rental then fry. um, and we top by the number of states thatributeed to that, remembering properties typically, so that would be membeating the classants. what memory the? amount of charges through it? that would be mem conducted. 
Conacetin this parallel of memory holds the charge. So prevent it from a meeting. um so past is deductains, what else will say? I.. resistance, that's right, right? 
That's something that can act as a symbol or ions disappear, get track. uh, and then the last one was um integration, right? And integration is only important for post thaturce, but the other three actually impact both the decormand and the spread of, you know, the movement of the close enough enourage and of the actionential. we also talked about well let's do this stuff back, so we talk about capacitives, which is how well the memory in the adon or in the then can maintain those ions that contribute to the burn. and we talked about some factors that can alter capacitants. or at least one. one, you bringing back from vacation. the channels are big channels, for example, how many channels we have, in this?, that provide opportunities for desires toape. What about conducted was what the termines conducted? 
it could be. It could be concentration of the ions or all the eyes are moving. because, you know, itend on the forces that drive the designs, maybe we have more or less, also what used to current member potential, because it's it's theme is old and I chemical is um concentration radiant in with theseyles. So whatever maximizes those going to maximize without it. 
What is going to increase what does it the interim or is thisistance? Which is not a good thing, right? It all one inter. 
When the accent is like thinner? Yeah, yeah, the diameter isame, and it artic for the items to move. Uh, if it's longer, then it's harder for them to make it from the beginning to the end, right? 
Anything else? could be just organiles that are in the way, like, you know, internal d of flames. Okay, uh, and then some basically you know, there factors involved is just what happens. high as of whatite charges me and you do cancel each other out. 
Okay, um, so let me talk us about selfaturering. continues conduction. um between is faster. So cell up to 50 higher faster, each one requires more angry., which one is temporal summations. That's 55 to one. high yeah. 
That's... right? You couldn't... Uh, it depends on the time. so if they come at the same time, it's theoralation, or is that the other one? 
have to be close succession. succession possibly come in at the same time because that will be the other. and that will be spatially usually that it comes from different places and haits together at the same time. It's just coming from the same place and up at the same time. time, right? So what it be? 
sick of you both. Yeah.. good is that? Yeah, all right.. 
How is stless intensityoded by action potentials? perfect our tiny little one sentence ess a question. on a test.. So that you know, this is the mosquito light versus by inst situation. 
So, yeah, if it's not to enhance the more action in frequency of firing actual, right? It's a sens turning around, why if it gets into the shark white territory? Doesn't it take, like group have to match that frequencyent. 
The group frequency that matters not the individual. I mean, each of individuals to it, but one individual can no longer match in frequency of action potentials, the intensity of the stimulus, so that where others come this kind of wall principle eyes. very good. talked about the. a while of the exon keep killer so had a few differencesomes. I don't knoworgeish, there's a note from the air. 
You can use that as a reference point and just outside of it was the par novel is it? And that comes after that? the par, and then comes out that very good. 
And so what is in the well, let's just go. it is in the note.. What is it? I channels? 
I'm sorry, I don't. The channels. Okay, thank you. 
Uh, so, yeah, there are leaf channels there and there's some house there at that's just an area where kind of the like the base ice sort ofablished the concentration across. concentration um difference across the where Ioss across the memory. And then in the juxtap paranoode, going to the going backwards here. or fun. I was DCacupied potassium channels that really actively tried to, um, essentially, uh, bring back theassium after the action potential. because during the natural sens show, you know, you have a lot of loss of potassium and in order to read establish theains that, you have the brain in back, and yes, the potassium to study potassium of contributes to that, but so do these um inwardly rectifying potassium channels are ju of paramount. um and then it has a paranoel. 
What's there? that like the approaching connections between them on element and the Axon? Yeah. radio highilding loose attached to the Exxon and not randomly attached, there is very specific location for the attachedment because through any salation modles, the violent has to be attached to deactive ring and basically everything is kind of kept in the right location, uh, and that important because you don't wanna cover up the nose of the air. other otherwise you're screwing, right? 
So, what's so important about the nondoramier? Itoops like. Right? 
It like keeps it so like it can keep it like speed so it doesn't slow down. Or like the um action or it so whatated region, right? The size of the current gradually goes down as some mas decided to take a left and put the right. uh you know, they just get somehow trapped so that the sizes occur actually goes down and having done. and those nodes have to beaced just properly so that the remaining current is enough to change the memory potential sufficiently to to open the so channelels in the nerve. so that's where the so channels are that are critical for the actual potential, and so therefore now that the sodium channel is open, now you can have a new supply of current that willain gradually die away as as it expressed down the time. 
But if they were not at the at the right uh distance from one another, is these nodes of right air, then you're sign would die. Um, and another reason why your sign would die if you use the violination because in that area, you would have lost extra loss ofasentially, so um, the decor of those currents would be might be greater than what the system can handle such that by by the time they be made into the nose, so little that not enough so new channels will you essentially regenerate they actually potential Are you good? that sort of? 
Okay, and then there's potassium channelsles, right? need to talk about. in the n note. the differences between electrical like chemical sc synapsis. chemical synaps. There what? 
Yes. Sorry. I was trying to like. 
Yes. chem slower because you have to have diffusion of a neuransmmitter from one neuron to the other and a much greater distance in addition as what the distance that spand in that afterolaps. So what is smaller or slower than the other, what else is different? that cig. 
Yes, electrical is almost simultaneous because what is passing there between the nur are the neur transparent that pass and in electrical synaps? Andthough there are no neur transmissions, right? So what's passing through? 
You can't have eyeons, you can have the nestingers, you can have others theyassing through there. Um and um what cannot pass through electrical space you started comparing that? So you cannot have an action condition with there. 
That's just not a date all these essentially local potentials, are local currents are that can they just buy off their pass through. um and it works just differently. So if we cause, the ES here and ISP the most acting are. I but those though there's that is still a direction and these uh electricalapsis, so they can be e rectifying essentially almost by ironannels. um, so there is that can be a direction to the communication. um they can be able to located, they can be signnogated. um what's cool about them is um they can also be between legal cells, right? 
We don't have synapses been a big real cells. But that chemical synapses per say, but electrical sy nurses are impossible, both between, uh theosals and between neurons, but not between clear toora. not mix it. And yes, so they're pretty cool for for anywhere in the way maybe you need super nice activity. wonderful to sell. let me talk about what and chemical scenariis for on the for the other. and I will make sure that you know the differencences between the three different types of festals that are involved here. 
So, clear codeicles are the ones that contain our transmitters, so they are also the ones that they neververt snackussles. Um, and they are different from that more reciples in that they are manified in the terminal, um, either using new or recycled materials. Whereas there is coruscles come from theoma because they're carrying difficulies by neides or other factides that have to be made in the in this in the in the center of the cells. 
It should cannot be perfectly. So that that probiblerive or micrubules and move on to microvelopments where clear vestibles are just, you know, locally made. What about? 
Hey, uh there like small range. make process that like. Yeah, so they can go anywhere. Where do they come their long before? 
is it? They can. They can also come from another , like the neighboring era, you know, so basically, they form through endocytosis, right? 
So they can and and you can have endocytosis with materials from the space where you can um add the um I know need uh mature multiviversicular body phase of the as so you can have stuff, content, actually an in theitters into the new diversical uh and the cell the lead end the so itself, so then you will have a bunch of little exysms inside it, basically, right? And then thoseysms are released through exocytosis where it's gonna be deep multiicar body that's fusing myth of the cell membr brain, and then releases its content to be char. uh as the cells. So let difference between a clear code that is load inO in art is in one case, you just release the contents of the Mexicles in the case of their vessiclesense four vesticles into the. space, you actually, uh, well, um,omes, uh release member bowel for memory, uh memor of you. 
I received like to his face on those typ still, so that's. And imp does because they they're cargo is much more so you wouldn't keep that together that's why we keep it in the um memory of the exiso, uh, so what is the cargoisomes? find that, you have las, you can have gardening, you can have mic gardening, you can have other things, basically anything in kind of ingredients that those' allow one cell to alter the the biochemistry, an under cell, and therefore it structure dysf functioning, because it can introduce new, tamplates to make new proteins, right? 
through the R over one cell theater, or any introduce micrene, which will alter transcription of RNA that synogenous to that cell, maybe change the levels of particular proteins that are made by the other cell. um et cetera, et cetera. I don't know what it doesn't. Okay. 
So then, steps of chemical organization and it did spend a lot of time on it, right? And it had different phases, so what do you have to do to a investical first? before it can be as societyist it has to join some sort of pool of something. 
So it's gonna be the reserve pool initially, right? And why but what is this reserve pool situation? What's happening there? 
It just has a lot of vesticles there are ready to be released when an action potential comes or calcium influx. Well, which leads to imposs., undergo a few things. for the reserve is like the maybe we use unit the future sometime, right? Yeah. filled up with the your own transmitter there? 
Yeah, so they they definitely start being filled up where they are in Uical, they first, you know, will be that short. Also, if it's a recycle that school that happens to somehow, um diffuse backold way to be reattached to the the resourful that can be I' for refeling so they're not mobile in this case. They're attached to one another like pearls in a string of pearls. um So they' connected to one another through sapin, and then what has to happen in order for them to be home, which is mobilization of esicles is the first phase of the whole.? 
Fast. Okay, um, yes, they have to be the Sinapson has to be used forrelated, and then it let's go, let's go the basketball. One forrelates the Sination. 
There still be a kind of sort of sorts, the only one we talk about the Chinese two. And why I look at Chinese to do that? Why wouldn't be do it just any time? 
calciuming. That's right, so it's a calcium activated Chinese, so you need to have calcium flux. You need to have some deorization that resol in calciumugs that even mobilizes the reserve coral bicycles of some esicles from the reserve noations. 
And then what happened to to these four bicyicles? They are like rather less, right? They're just gonna start, like now they're mobile so they're just gonna go with the currents, basically, nobody's moving them. 
They're just in possibly, and then what happens?? Yes, so there these proteinathers that they will just buy accident coming in contact with and essentially catch them. And they vary in size and so the further away they are from the postptic memory it will most likely be that the longest one of theseangering proteins are the ones that will get caught first and then it kind of yelles them around, just imagine like pinball basically, once you're attached it is gonna impact the movement of that icycle the trajectory of it, and it is gonna get tangled into shorter one and it could get tangled into even shorter one. 
So gradually these end up essentially pulling the vessle closer to the the so green, right? Um, but that's not enough. Now that's just really close to the memory, still has to do something else. 
So after so this was darking when you get table, you know these protein, 10 type of things. And then then comes crying, right? and that's when you have these essentially sellesia molecules linking up between the bicycle and the terminal, which hold the bassical, even closer to the sub brain. 
And to remember there are these snares and T snares, the me snares are provided by the vesicles, the T snares by the terminal. thus's why they named Vity. and anyone remembers who they are the names of them? And we of the. so snares, the two Ss are the snares. There' third S. one of the third, one of the other S is is uh G snares, still set down 25 is a T snare. 
And then there are some other proteins there too. And those proteins just make sure that the vesticule is now not only close to the memory, but it's really exactly at the active side, right across from the uh the receptors or the other side of the syn, not just anywhere on memory. And so among uh 18 is one of those proteins that is part of theagic side, um scaffolding em make sure that the only place where we comes together where really best codets, you know, imposition is right across from the receptors in the.C we remember the synapses is not just, you know, a terminal and another terminal is swappping synaps they' like shut like this, the holes in the shower head. 
There are these tiny little active zones that are essentially withing absence on there. So you wanna make sure you're not outside of there. thereivers is or the contents of the vessal will never make it to the right spot. Right? 
All right, so now as school is seriously tearing to theresyptic memory from the inside, right? And what happens next? Uh, soon after attacking by the Ser complex, then is activated by the by calcium and the stretches it apart, creating the best core.. and so so Sin after tagment is one of those proteins that are on the surface of the vestule, but it has to integrate interact with those weers and T snna to form the complex that will then be able to open the form and then the calum activates it yeah. 
And then unless it opens what one moves theoreansmitters out of there. That's up for quiet. Nothing, right? 
Concentration gradient, because they are at a very, very high concentrations in the esicical place to some sort of simple order, some sort of hop, something that has, you know, accumulated demide thatust all you have to do is a little bit important is things just this few out into the anactic left.. Now we talked about various proteins along the way, that men through, so synapsin, that we had syntaxin, we had synapabbin, then we had 825, among 18, then had snap tagman, just kind of tried to remember each one he lived. They been stepped in what order, they need to be become engaged. 
Um, because that's an easy way for me to ask the order of these, for example, because the I know you can catch you picture the whole process in your head is what I'm holding for. I hope that you don't just sit doesn't memorize fi versions of the right order. I hope that means that you're actually, like, seeing the whole process in your mind eye but I ask you that question. 
So in my mind that's not a rezation question because it's for like, like, do you do you see the whole process in your head? Okay, so then we release the number of transmitter. and it's very consistent, right? how much more transmitter is really east. for a single esicle, which is what the quantumous is the mant materit contained in the vessle, and theitosis of those into the snaps is very efficient, so very consistent, you will have particular around in a particular caps. um type as in, like, what kind of normansmitter it is and, uh but it's gonna be different for loob being different for us to clean et cetera. um so allo is very consistent, so how did we know that? 
Is a new place of remember. So it was an experiment, kind of a classic experiment when you were looking at typical release in the normal muscular junction. Initially, and what they were doing is they wereasuring post syneptic potential changes. 
It's just called endplay potential. And what they noticed is that depending on how many vesticles were released, the endape and short would change kind of like steps. It wasn't like a continuous thing, and from that they were like, oh that. that's how they kind of figured out backwards going backwards and it seems like there is very consistent amounts of neurransmitter in classicalles, because this this line is not reized. you know, the the amount of their transutter that hits the most have thecovery is not a continuous variable. like it's it's gonna be kind of in steps, and so let's have these realized all yet. 
They're setounds released. um and it depends on how many festals are being straight. Um So then they also talked about and we talked about, but yeah, so then what once they understood that, they were able to look at what is the probability of the release, because now they have juststood about how much of a change the post syptic potential equals the contents of one esical. So then they were able to say, okay, well, determines when there are any vessicles are released. and they are not very quite a bit from scenat to synyn, so not some of the synapses are very reliable. 
You have an action potential, that thing has been the release messical, but others will have only 10% of the time of the actionlease the les. So it's between about 10 and 90%. that neuransmitter moving be released throughytosis duringaction potential. And even then, most of the time it is just a single besiccle, and that's enough for the synab to, you know, do its things. 
It doesn't mean that, of course, there's gonna be an extra potential in the post synaptic there are because again, you need that a lot of local potentials, um, so maybe before you happen potential. Um, so what determine of this is something that went through last time? What determines whether there's gonna be vessical release or neuransmit release, vess scientosis.. 
What are the things that have to be there or it could happen? Can you say well? cost channels? 
Yeah, you need to have calcium channels. They have to be in the right location, right? they have to be right near those snares. 
Otherwise, the probability deal to calcium finding the cement detachment is gonna be lower, right? What else do you need? You need to have a calcium gradient, like, so the higher the external uh calcium concentration it is, the gradater is going to be the driving force where the calcium to enter, or we more ripple enter in the shorter amount of time, I'll just channels are open. right? 
And so again, that's gonna increase the probably do that, the calcium will find the calcium censor? What else do you need? Or what else can determine how reliable that see our system? 
So the number of thousand channels, concentration, calcium, Capacinins. Yes, on the way there, I guess. to even find that I should potential there. Um, because that's what ends up changing the member potential to open those things which created. calcium channels. 
You need to have esticles that are appropriately filled by those transport proteins. Could it also depend on what type of like retrieval it is if it's like bulk retrieval or like kiss and leave? Yes. 
Well, go for some reason, because we know releases a thing. most of the time em are helpful withles don't seem to be released, and I don't think beingy fully understand it. at least under normal circumstances. I have read about this because of how people have asked questions and artificially we can be complete festicals, in know they. and things like resip that based the vesticles need key before they even be released, and so therefore, you' basically old empty or empty, duringittosis, but under normal circumstances and then help the organism, for some reason things get filled very consistently before. It really you're right, it could be theoretically small possibility that maybe one of thoseissen state things get released, you know, go on to go exercise or see before the vesticles is is fully filled. 
It's surprising that we don't see evidence. in a way, that suggests there's some kind of mechanism involved that because I'm not aware of that you that happening right. Okay. I you say else? 
It's good enough. not. All right, what is that' determine your transmitter these probability of one action potential. We just talked about that as um, what are the components of the sylective cleft and how did they work? 
How did the facilitate chemic transcription? starting on the very outside of the snaps. and they deliate the middle. What are the things that are the very dary outside? 
talked about these molecules that are actually calcium dependent, because they are kind of folding the scenats together and stabilizing the senat, ready? There are some other adhesia molecules, um, further in. um but also provides are girls support to the synaps and also connect the pre synptic machinery to therive location on the post synctic summary. so that you have these matching because otherwise, the end the probability that a transmitter that's used from here finds every subject over here is going to be much more. So, we tucked about direction or licen, those were two that are in there. lining up receptors, vent through these sites, basically.. 
And so, in the case ofuaturic synapsis, you will have scaffolding proteins called PSD 95, that's just what ones that are connected to the uh post synaptic Nathesia molecules or detectic place, and then base, they the scaffolding on which you can have receptor sitting or being moved by a word proteins. in and out, okay? So you will have um anemity every sectors that can be inserted into the postsyaptic density. um, and that happens with calcium therodulatedependentote five needs two and two, basically gets most formrelated, or if it activated and it's going to forcephorate the receptive protein itself in a certain way, such that is not move up in and be, you know, expressed on the surface of the most scantic neuron. Okay, um, and it can also postorlate in a different location of the same receptor molecule that can cause internalization of the receptor and removal from the surface of theinus.. 
And then we had stargin or tart, which was a kind of like a little engine that runs some of the PSD 95 and can carry on it and parceptors from the peripher of theaps to the center of the synapse. Why is that important? Why would you want toact or would you would have? 
Essentially that surveyor brightly semength, right? Because the synat becomes more reliable. The communication becomes more reliable if the receptors are right across from the east side, as opposed to the this thing that is about fine the very free. 
So, if they're in the hurry furry, a lot of even repeated firing, a lot of similar transmiters necessary before the concentration of her transmitter in that space is high enough so that it's gonna relyably stimulate those per referral emperorsceptors. But if you move over to the center, the chances are they going to be stimulated and those chances will increase. Do you that you just a sequel, right? 
And so basically the synaps is more sensitive now, and and well how. And then for Gab Sinaps says, what those the end of to 95. That is, this gap allilities. 
It's also cardobic gold andut dark.... So, we established that I didn't know that the Afghan can moveceptors that only similar to tar um, and there is not another, so it's basically taking the job of both PSD 95 andAR, is just all living place looking can move them.. I'm so. 
Am I forgetting anything? An, like, inurse psychiatric disorders, sometimes the issue is this machinery is not working properly and you will not having a receptors, or they may not move to the right location, uh, or you may not have release of the right place because the the decreaseaps in the postos are not l line up properly any of those things will basically impair communication and and learning because it will impair ability to change the strength of theaps., yeah. Okay. 
What's the function of the exercise majors and let's just start that? So why do we have exercise we? Why don't we just have nothing between cells? 
I mean, essentially it's almost like I remember the umosh. There are filaments that our wholey space that in a way they are like spacers, right? They also hold water. 
They' essential or holding water and they do this by containing hyeronic acid in that location. It's also a location for a bunch of things like growth factors and other chemicals that they nurtured just cells or determine how how they establish corrections and maintain connections. And then what are per heads?? 
That's around theadi? um, and basically they are these features structures, well, they're dynamic in assessment. I let's say you're today they're going to be all layer, right? 
And basically they permit just kind of really nearly fasticity to for aurry. so they kind of maintained the status school life testing involves. And then at night, they tend to break down, um and then that allowsasticity to take place. It makes it easier for things to have her, because it's not there to block the way of molecules, doing their way. and this, you know, just made up by sugar and protein. 
Most of the time they are around smaller inf ne around, but they can also be around around neurons. the less. And then the very last time you talked about it is that you kind of revisited the uh saps and we that the contribution ofracites and boglia, not that you have a greater understanding of how cells in the community can to one another. and re reviewed basically that aocites in microplia and, you know, support synapses, um, support the functions by providing structural support, by also by reoving spines and eliminating synapses and in use of micropia, directly, um, by releasing chemicals that are gonna, you know, destroy two things up. um, where's exercise would be able to support synapsis by the writing nutritional support, structural support, but they do much more than that, right? So they can alter the level of neurransmitters you to synx very often. 
They haveides have transporters of their surface, so the reopognore transmitters is not necessarily happening or involved, a return of the neuransmitter to the presyptic neur. Sometimes it's actually taken up byides to some, they can actively regularly levels of neurotransmitting to synast and therefore they can regulate and direct the how much stipulation those postact perceptors to the ad. So they can regulate the activity of the sn steps and the actual moral communication. um they can also alter the level of potassium and some other things that again, the play a role because it's been auttric potential and therefore it's gonna determine, you know, whether those cal which have also opened and there's gonna be more of these. um they can also, um release their own transmitters, right? 
And some of these are transmitters that neur wrong can also release, but some of them are other things like eating, that neurosones as much toate, but, uh, they also cells can use them. and uh whenever it's in communication molecule that's released by gosel be, but we calledleotr transfigures instead of neural transmitation rate. So you're packing, which makes me think that it's time, and that was the last one that I wanted to strong.