when my oldest son was about five he asked me one of those important life-changing benchmark questions no it wasn't the where do babies come from question I was actually ready for that I had like diagrams and everything what he asked me was dad where do thoughts come from really really kid is that what you want to know so I don't know why I just spit out something like thoughts come from your head son and that kind of shut him up for a while and now about 10 years later I guess he's finally ready to hear where thoughts really come from so here it goes and I wasn't actually lying to my son I mean thoughts do come from her head in particular they come from our brain to be even more specific that come from these small cells in our brain called neurons we have about a hundred billion neurons in her head and all these neurons have basically one single job and that is to communicate with each other it is vital to understand that every thought every feeling every emotion every memory you've ever felt is because these billions of neurons are communicating with each other in different ways what's important to know about these neurons is they never ever touch each other which was the motto of most of my girlfriend's in high school there is always a space or a gap between neurons in this gap is called the synapse so then how do our neurons actually communicate with each other across this gap and the answer essentially is they throw chemicals back and forth at each other in these chemicals are called neurotransmitters in how important are these neurotransmitters well I mean if I was pressed I would say they are everything every thought every single memory hell every emotion you've ever had is because of specific chemicals of these neurotransmitters that shot across the synaptic gap between neurons in our brain okay so how many different types of neurotransmitters do we have in our brain well scientist estimate there's anywhere between 30 and a hundred with about 10 of them handling 99% of the functions in our brain but for the purposes of I don't know an intro psych class or AP class or an IB class you really only have to know about I don't know I would say about 4 or 5 so let's go through and quick 1 important neurotransmitter is called acetylcholine good luck trying to spell that so scientists just call it a CH for short in this neurotransmitter is involved in voluntary motor movement in memory so every time you move your body you're actually firing they see the choline in the synapse in between our neurons I guess a good practical example would be something like the black widow spider the venom from a black would have spider increases see the choline production in our brain to the point where we'll start ceasing because we can't control all the voluntary muscle movements lack of acetylcholine has also been linked to diseases such as Alzheimer's a second neurotransmitter you should probably be aware of is called dopamine dopamine is involved in things like motor movement in alertness drugs like cocaine increased dopamine levels in our body making us feel very I don't know what it really feels like I've never taken cocaine but they say energetic cuz it's stimulant lack of dopamine has been linked to Parkinson's disease and actually an overabundance of dopamine has been linked to schizophrenia another neurotransmitter you should be aware of is serotonin serotonin is involved in mood control lack of serotonin has been linked a clinical depression so if you're taking an antidepressant like paxil a prozac or zoloft then logically you would know that that drug probably increases serotonin levels in the synaptic gaps in our brain one of my favorite neurotransmitters is called endorphins endorphins are really dealing with pain control for those of you who spend a lot of time exercising in particular those of you run long distances your body will release endorphins in response to the pain I believe they call that runner's high I don't really know anything about that because running just sucks opiate drugs like heroin tend to mimic endorphin production in our brain I guess we can do a couple more quick we have Naropa nephron which is involved in alertness and arousal lack of it has been also linked to depression we also have one called gaba gaba really deals with sleep issues those six are probably gonna be the only ones you'll see and intro to psych exam so now you have kind of a conception of what i know a tresor is and what they can do we still have to address how neurotransmitters actually get around our brain in other words how those neurons actually toss or throw or fire the neurotransmitters from one neuron to the next in the best way to do that is to go over some neural Anatomy or the structure of a neuron let's start with the dendrites the dendrites are like like these root like branches or these arms that come out of the cell body of a neuron and they have basically one job they're like I don't know they're like dirty old men and what a dirty little men do yeah they grab onto stuff in dendrites grip onto stuff too but in this case they grab onto neurotransmitters their main job is basically to reach out grab onto neurotransmitters from the synapse and send messages to the rest of the neuron attached to the dendrites you have the soma or the cell body it's basically like the brain of a neuron below the cell body you have something called the axon the axon is a wire like structure that sends electrical messages from one side of the neuron all the way to the other surrounding the axon is a layer of fat called the myelin sheath the myelin sheath like a rubber around the wire helps insulate the electrical signal traveling down the axon when the myelin sheath breaks down you have a disorder called multiple sclerosis at the bottom of the axon you have the terminal buttons I've also heard it called axon terminal or n buttons and the function of these terminal buttons is to store neurotransmitter that could be fired across the synapse to the dendrites on the next neuron okay so how does this hole work when a neurons doing nothing it's called resting potential and has a slightly negative charge when the dendrites grab on to enough neurotransmitter the neuron then will reach what we call threshold it's either going to fire or it's not going to fire that concept is called the all-or-none response kind of like putting your finger on a trigger of a gun the gun will either do nothing or a bullet fires completely there's no halfway or partway firing so when the neuron decides a fire it goes into a process called action potential in what happens basically is a little portal opens up on the axon in in rushes in positive ions mixed in with the negative ions inside the axon causing an electrical charge to travel down the axon now in case you want to know these ions could be many different things but they usually potassium and sodium but I don't think it's all too important now an electrical charge travels down the axon until it gets the axon terminal and the axon terminal buttons then fire off neurotransmitters across the synapse to the dendrites on the next neurons that are awaiting it when the neurons receiving the neurotransmitter across synapse had enough they reach their threshold and perhaps go into action potential the axon terminal on the original neuron will then go into the synapse and suck up the leftover neurotransmitter and we call that process reuptake I know that all sounds very complicated stuff that one more time so the dendrites grab onto these chemicals called neurotransmitters it could be serotonin it could be dopamine whatever it is when the dendrites had enough that reaches its threshold it then sends a message to the soma to go into action potential when the neuron goes into action potential it opens up a small portal on that wire called the axon the axon lets in positive ions cause an electrical charge to go all the way down the axon once electrical charge reaches the axon terminal that neuron then sends neurotransmitters across the synapse to the next neuron awaiting it whatever neurotransmitter is not being used the axon terminal then suck it right back up in a process called reuptake you know um they take this time to give you guys a special bonus we're gonna talk about drugs because drugs for the most part mimic or block neurotransmitters in our body in fact drugs - only one of three things some drugs are what we call agonists agonists are drugs that mimic neurotransmitters so they latch on to the neuron the neuron thinks that that drug is a neurotransmitter then it goes into action potential and it fires other drugs are called antagonists antagonists latch onto the neuron the neuron knows it's not the neurotransmitter and it stops a neuron from going into action potential and firing the third thing a drug can do is it can inhibit reuptake in other words when the axon terminal tries to suck up that leftover neurotransmitter some drugs block the axon terminal so it can't suck up that leftover neurotransmitter leaving too much in the synapse causing us to feel the effect of that drug an example would be cocaine cocaine is a dopamine reuptake inhibitor so when a neurons firing dopamine the axon terminal fires it out and then it tries to rehab take it or suck it back up the cocaine blocks the axon terminal from sucking up leftover dopamine thus we have too much dopamine in the synapse thus we get high up cocaine in fact almost every single antidepressant drug is a real take inhibitor the most oftenly called SSRIs selective serotonin reuptake inhibitors drugs like paxil prozac or zoloft they go into our body in they stop the axon terminal from sucking up the leftover serotonin in this case we raise serotonin levels in our body hopefully alleviating depression okay so there you have it neuroanatomy neural firing North transmitters and drugs in just a few minutes now obviously I really simplified this there are very smart people spending their whole lives starting this electrochemical process called neural firing but since the next season of The Walking Dead comes out soon I gotta go been to watch I don't have a lot of time mostly because my wife's gonna make me watch that show this is us it it's alright just it makes me cry every time whatever some you know I'm talking about alright later [Music]