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0:04
>> So, what I'd like to do then is transition to the next topic. That, and that next chapter is on the topic of, ultimately on the biological basis of behavior, or what we call neuroscience and behavior. And we're going to transition to what seems like a separate or different altogether topic, but there's some cool experiments going on that I'd like to tell you about, some cool correlations. And so we'll use this material from the first chapter as we start to explore this study,
0:36
and there are probably a number of things we're going to do in here that I want you to pay attention to, that even if you've already covered this material, it may be, for some of you, something that you've heard a lot about before, but we're gonna talk about the nervous system in general, we're gonna talk about the brain, and then we're gonna talk about when people feel happy, what happens and what goes on in the brain when people are happy. So here's what we're going to do.
1:03
We have some key questions
1:06
over the next two times that we're together, and we're going to try and answer these questions. Ready? You don't have to write these down, but they're cool questions. I think it starts with this: how and why are addictions formed? Anybody know somebody with an addiction, and how did it form? How did their addiction to something form? What sure. >> Female Student: I think, I've noticed, for example, my uncle, the one who, my two uncles, they both did drugs.
1:38
But the one who stayed addicted to it longer was the one who needed acceptance. >> Okay, so there was a difference. She shared that two of her uncles both experimented with drugs. One stayed with it a little bit longer and he seemed to be somebody who needed more acceptance or more, is that the word you used? >> Female Student: Validation. >> More validation, and so that addiction formed as he continued to use this. Uh-huh. >> Female Student: My friend's mom used to be an alcoholic
2:06
while she was in an abusive relationship and then after that, after she got out of that relationship and went to AA and sobered up, she married another man and then after divorcing him, she has hoarding problems. >> Okay, so there seems to be, she said, who did you say? >> Female Student: My friend's mom. >> Friend's mom dealt with alcoholism, and then after that, kinda overcame that, but then a series of events, like a divorce, caused her to even do some addictive behavior
2:33
like even hoarding behavior, is that right, alright. How and why are addictions formed, yeah, go ahead. [student speaks off microphone]
2:54
Yeah, so if you're in that environment, let's say you have family, friends, older people in your family, brothers, sisters, whoever, if it's part of the environment, it could trigger you or lead you to try and experiment and maybe become addicted.
3:09
What drug, which are the most difficult addictions to break? Ready, five groups of people. Let's say we gave them five different drugs. Which one is the most difficult to break, ready?
3:26
And we can't do this ethically, but if I took 100 people and say, "You, you're gonna go drink alcohol for a year. "you, you're gonna go have marijuana for a year." This other 100 are going to go do cocaine, this other 100 are gonna do nicotine, and this other 100 are going to do heroin. Got it: alcohol, marijuana, cocaine, nicotine, and heroin. Is that five, yeah.
3:51
We're gonna see who comes back addicted. Which substance has the highest, most difficult, the highest addiction rate and the most difficult to break?
4:03
You'll know the answer in just a minute. What do you think? By the way, probably one out of every three people that go away and try this, if we took 100 people, 33 are going to come back addicted. The highest, the most difficult addiction to break and the one that is most addictive is nicotine.
4:22
Nicotine, about one out of every three people are going to come back addicted to it, and they're going to have a hard time breaking it. The next one, about one out of four are going to be addicted to what? Yep, number is, and I'll just read it off to you so I make sure I give you the right numbers again this time. Number four, about one out of, not one out of three but about one out of four people are going to come back addicted to heroin. Same with cocaine, might be somewhere around
4:46
one out of four, maybe one out of five people are going to come back addicted to cocaine, and then maybe somewhere around the neighborhood of one out of six for both alcohol, slightly less for marijuana.
4:59
These addictions are hard and difficult and it depends a lot upon the interaction between our own brains, the way they respond, but also what happens in the pleasure center of the brain, which we're gonna learn a little bit about. In this pleasure center of the brain, some very, very disturbing things happen. We don't send away 100 people and ask them to do marijuana and ask them to do cocaine and ask them to do tobacco, it's not ethical, but we have sent rats away
5:28
and asked them to do marijuana and cocaine and alcohol. And guess what happened when we send those rats away and we say, "Come on back in six months or a year "and check in with us."
5:39
These rats come back
5:43
in a very unique state. See, the reason we use rats in some of this is because their brains are very similar to humans', and there's this pleasure circuit in the brain that looks a lot like it does in a human. And so what we've done with these rats is we've drilled a little hole in their head, it doesn't hurt them, well, initially it does, but you give them a little bit of Tylenol and you drill a little hole and you find this little probe and you find their little pleasure circuit
6:06
and you stick this little probe in there and you hook it up to an electrical impulse, and every time that electrical impulse goes off, like they push a bar, it stimulates that pleasure circuit and they go like this: whoo-hoo, whoo, whatever rat says. [students laughing] The rat likes that, whoo-hoo, like that. [student laughing] Rats love this pleasure center. It's the same circuitry that's impacted by things like cocaine, okay? So we send rats away and we addict them
6:39
and it goes just like this all of a sudden, they are wanting that pleasure circuitry to be stimulated because they like it and it's just like an addiction in a human. They go like this, whoo, I like it. You know how strong it is?
6:51
When a rat goes away and gets addicted to this pleasure circuitry being stimulated, they become so addicted that we take it to find out how addictive is this? And this is why we're going to study the brain. This is why we're going to study addictions in nerve cells, because what happens to this rat is shocking.
7:10
We take a rat, we put it on this side of a cage, and way over here, on this cage, ready? We stick him into what's called a goal box. So on this side of a very long skinny cage, they can push a bar that they're used to and it gives them brain stimulation and they go like this: oh that feels good, oh that feels good, and they keep pushing it to exhaustion. So the question is now: how important is that pleasure circuitry to be stimulated just like in a human?
7:43
How important is it, and they keep pushing it. So they put two other rats in the same box. They put a hungry rat and a thirsty rat,
7:54
and they put between them, over here in this goal area, the light turns on right here and the rat is now able to push a bar and get brain stimulation. And right next to it, the hungry rat could push a bar and get food, and right next to it, the thirsty rat can push a bar and get water.
8:14
The light turns off, they have to cross a grid, and they have to go to the other goal box 'cause this light's now on, and the rat can push this bar and get pleasure, or rat number two could push it and get food, and rat number three can push it and get liquid.
8:32
That's a cool little study. Light turns on, they run across this grid and they run across like, ooh, over here. Push push push push push, they do that. With one very interesting little twist.
8:47
The gap, the floor between them, is metal, and they electrify the metal, and they want to see how high could they electrify the grid before the rats won't cross to get what they want. So here's the rat pushing the bar right here in this box, going, "I like this feeling, I like food, I like water."
9:10
Three rats, the light turns off, that light turns on, they wanna cross that grid and it's now electrified, it hurts their feet, they get shocked. And so the rat that wants water goes like this, touches it and goes eeee, well I don't know if it says that. [students laughing] You can get it to a point, to a high enough electricity level, shock level, they will touch it and say it's not worth it. I will die of thirst right here. [students laughing] And the rat that wants food will touch it and go,
9:42
"I'm not crossing, you've hid an ampage, "whatever, a level, I'm not crossing." And the rat that wants brain stimulation does what? It crosses and goes over there to get its brain stimulation.
9:57
Is that pretty powerful? Our brains are the same way. Do humans make the same sacrifices to cross the same thing, to get the same shock just to get that? By the way, they don't let these rats die of starvation or water, they give them water, but they could set this up high enough, they won't cross. You almost can't get it high enough for these rats that want brain stimulation.
10:20
What does that tell us about human addictions? We are going to learn about addictions in here, and to do that, you have to understand something about neurotransmitters. You have to understand how they work. By the way, it has major practical implications because we're gonna talk about things like food that stimulate this pleasure circuitry, addictive things, but so does Parkinson's disease worked on the same process, so does Alzheimer's disease, so does saran gas that they just recently used
10:44
in another country to kill people. It's the same thing, it works on the neurotransmitter.
10:51
So addictions are the same thing
10:56
that help us answer questions like, why do people like pleasure? What happens when we biologically feel good? By the way, at the end of this topic, you're going to be answer this question, what happens when you feel good? If I ask you this question, do you feel good?
11:12
You're going to be able to give me the answer. I'm gonna tell you why addictions work in a way that your brain says, I feel good, and a substance does something that triggers your brain to go like this, "Ah, this is normal you, this is normal, I feel good." If you're sitting right now and you're kind of content, you're going, I feel good, I feel good.
11:34
When we take a particular substance, it goes like this, like cocaine. Cocaine has this very powerful effect. You go like this, your neurotransmitters go like this. Here's your normal dopamine when you're feeling good. I feel good, I feel good, I feel good. You take cocaine, it blocks what's called the reuptake of this particular chemical called dopamine, a neurotransmitter, and it keeps sending a message. Make you go like this: I feel good, I feel good,
11:59
I feel good I feel good I feel good I feel good I feel good I feel good I feel good.
12:04
And what happens is your body likes that, your brain likes that, just like this rat liked that, you go, [gasps] I like that feeling, that feels good, I want more. But your brain does something really weird. Your brain sees this and it goes like this, it goes, huh! There's a little part of your brain that goes [gasps], "You feel too good, stop making "whatever you are making, turn that off."
12:28
And so your brain turns off a part of your natural brain chemistry that's involved in this, and now cocaine fades away, and your brain is not making that natural substance, and it's made corrections, so now you don't just feel good. You don't feel good at all.
12:47
And that's the beginning of a what? >> Students: Addiction. >> It's the beginning of an addiction. You say, "I need more to feel good." And 30% of you or more are going to walk away trying that and getting addicted to it because of the brain's capacity to say, "I like to feel good, there's nothing wrong "with feeling good, it's just too much." That little part of your brain that does, is the same thing about tickling. Can any of you tickle yourself? How many are ticklish?
13:11
Let me see your hand if you're ticklish. How many that are ticklish, go ahead and try and see if you can tickle yourself. Can anybody tickle themselves? [students chattering] How many say guys, I'm ticklish, and it doesn't work to, don't raise your hand if you can tickle yourself, 'cause that's kind of odd. [students laughing] why can't you tickle yourself? Because guess what, your brain goes like this. You reach over and you start tickling,
13:32
but if somebody else did, it would make you very ticklish. And I see some of you doing that to your neighbors, stop it. [students laughing] But if you go like this to yourself, guess what, there's a little part of your brain that goes like this, "Oh, don't get so excited, it's just you." [students laughing] that's what it says.
13:49
So it's the same body part, the same thing being tickled, but a part of your brain goes, "Oh that's just you." well, see, there's the same part of the brain is kind of the analogy of, [gasps] your brain, I'm making too much of this stuff, darn it all, stop it.
14:03
It's the beginning of how people get addicted. In order to understand that, we have to realize that there's biological consequences, neurotransmitter consequences, that ultimately affect the brain and the mind and just like mental illnesses, there are consequences to mental illnesses.
14:24
We sometimes call them chemical imbalances and those chemicals are almost always at the neurotransmitter chemical level. It's why we call them chemical imbalances. How many know somebody that's been diagnosed with a chemical imbalance? See your hands if you know somebody. About 10%, 20% of you have raised a hand. What does that mean? Where did that imbalance come from? What chemical, and you're going to know all of that. The nervous system goes like this. The nervous system is an electrochemical
14:53
communication system, we're gonna talk about the chemicals, but we're also gonna talk about the electricity because some drugs stimulate chemicals, some drugs stimulate electricity in the brain, and the brain uses both. It uses electricity and it uses chemicals. That's why we call this nervous system an electrochemical communication system, and it's all about communication. One nerve cell communicating to the next nerve cell, telling it to fire or send a message
15:18
or pass on the message, and it does that both using electricity and chemicals. That's why an electrical problem is very dangerous for people. Any kind of electricity, it could just reset the brain. People could go into seizures with too much electricity in the brain. It could be the result of some things in your brain going awry, we'll talk about that, but it's also injecting things like food, or feeling good chemicals, influence us. The divisions, there are different, very quick divisions,
15:49
like what we call the central and the peripheral, that big difference, we're going to spend most of our time talking about the central nervous system, but there is a peripheral nervous system, and this peripheral nervous system kinda gives us different ways of sending information. So I go like this, ready? When I go like this, I'm using my peripheral. It's on the outside, the periphery.
16:13
Things like breathing are somewhere, I guess you would say, on the peripheral, but the brain, the spinal column, all of that, central nervous system. We're gonna spend a lot of time talking about the central nervous system in here. You should go look for this particular figure, graph, whatever, in your textbook. You'll find it, just look at the peripheral versus central, it's in the textbook so you don't have to write it all down today in these notes.
16:42
What I'd like to do is talk about neural pathways because this is the basis of where we're going. Sensory nerve cells, inter-neurons, and motor neurons.
16:52
In a reflex, that's the most simplistic pathway, there are a billion inter-neurons. An inter-neuron is like right in the middle, think about the spinal column. And now here in the sensory, right now when I move my fingers or I move my hands, that's the sensory, and then there's a motor neuron
17:13
that helps me as I move the muscle, it's called a motor neuron. So a sensory nerve cell, for example, picks up the smell, the heat, the light, the touch, temperature, those are sensory nerve cells way out on the periphery, and then they send information into this inter-neuron, kinds of makes a decision about what to do. Oh, it's hot, you just touched, move your finger,
17:42
and that's the motor neuron. And so this inter-neuron goes, [gasps] "hot, move your finger", and the motor neuron tells you, "Move your hand."
17:49
this is a very, especially reflexes. Today, I don't know if you all get in your car and it's hot outside and you've ever sat down on a hot seat, weren't paying attention, eugh, and you jump right up. That's a reflex of action. Or if somebody pokes you when you're not looking and they just kinda poke you, you're going to react, but your brain doesn't have to think about this. If you were to go stick your hand out like this and touch something very hot, your brain's not even involved in that.
18:11
If this is a hot plate or a hot car and I'm sitting here and I go like that, that's a very quick inter-neuron that's making the decision to the motor neurons saying, "Move your hand before it burns." If it had to go all the way to the brain, it'd go, "I wonder what that is, "it must be a hot plate, I wonder why, move it", [laughs] you'd burn. So the inter-neuron goes gahhh, and that's a lot of reflexes.
18:39
Make sense?
18:42
Quick reflexes.
18:44
Nerve cells are the basic building block and they look like this. What I'd like you to do is look over nerve cells
18:54
and pay particular attention because next Wednesday,
19:00
next time in this class, what we're going to do is spend time looking at nerve transmission, neural transmission, cell to cell, nerve cell to nerve cell. We're going to look at how that occurs by looking at an individual nerve cell, a neuron, explaining it, talking about it, because guess what? We can understand addictions, we can understand chemical imbalances, we can understand a little bit about why pleasure and where it comes from, if we understand
19:32
two nerve cells and how they talk to each other using a neurotransmitter. So on Wednesday, I'm gonna cover this in detail. You're gonna be able to answer questions like, [gasp] I know why addictions get formed, how they're strongest and have a difficulty breaking, and then what we do with chemical imbalances or things like other addictions or disorders. Alright, we'll see you next time. >> Narrator: Biola University offers a variety of Biblically-centered degree programs,
20:00
ranging from business to ministry to the arts and sciences. Visit biola.edu to find out how Biola could make a difference in your life.
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