Neuroscience For Psychology
Summary
TLDRこのビデオスクリプトは、脳の神経細胞(ニューロン)がどのようにして思考や感情を作り出するかを説明しています。ニューロンは約1000億個あり、相互に通信することで思考や感情を作り出しますが、直接接触することはありません。ニューロトランジター(神経伝達物質)がニューロン間のシナプス(ギャップ)を越えて化学的に通信を行います。アセチルコリン、ドーパミン、セロトニン、エンドルフィンなどいくつかの重要なニューロトランジターが紹介され、薬物がこれらのニューロトランジターを模倣したりブロックしたりして作用する仕組みも説明されています。
Takeaways
- 🧠 脳の思考は約1000億の神経細胞(ニューロン)によるコミュニケーションから生まれる。
- 🚫 ニューロン同士は触れ合わず、その間のギャップ(シナプス)を神経伝達物質(ニューロトランジター)が飛び交うことでコミュニケーションが行われる。
- 💊 ニューロトランジターは思考、感情、記憶など全ての脳の機能に関与し、30~100種類存在すると推定される。
- 🏃 アセチルコリンは筋肉運動や記憶に関与し、ブラックウィドウの毒液やアルツハイマー病と関連がある。
- 🎯 ドーパミンは運動、警醒に関与し、コカインなどの麻薬はドーパミンレベルを上昇させ、パーキンソン病やスチゾフレニアと関連がある。
- 😌 セロトニンは気分のコントロールに関わり、不足するとうつ病に陥る可能性がある。
- 🏋️ エンドルフィンは痛みを制御し、「ランナーズハイ」を引き起こす。ヘロインなどの麻薬はエンドルフィンの働きをまねる。
- 👀 ノラペプチンは警醒、興奮に関わり、GABAは睡眠問題に関与する。
- 🔋 ニューロンは静息時(resting potential)には負の電荷を持ち、ニューロトランジターを受け取ると閾値に達し、アクションポテンシャル(action potential)を始めることがある。
- 🔁 アクションポテンシャル中、陽イオンが流入し、電荷が軸索(axon)を下る。電荷が端末ボタン(axon terminal)に達すると、ニューロトランジターがシナプスを飛び、次のニューロンのデンドライトに向かう。
- 💊 麻薬はニューロトランジターをまねたり、阻害したり、再吸収(reuptake)を妨げたりして脳内のバランスを乱す。
Q & A
子供が「考えはどこから来るの?」と尋ねた時、親はどのように答えたらよいですか?
-親は子供の理解レベルに応じて、考えは脳からのニューロンの通信によるものと説明し、さらに詳しく知りたい場合は、ニューロンがどのように通信するか、そして神経伝達物質がその役割を果たすかを簡単に説明することができます。
脳にはニューロンがどれくらいありますか?
-脳には約1000億のニューロンがあります。
ニューロン同士はどのように通信するのですか?
-ニューロン同士はシナプスと呼ばれるギャップを介して神経伝達物質を投げ合いながら通信します。
シナプスはどのようなものかを教えてください。
-シナプスはニューロン同士の間に存在するスペースであり、ニューロンが神経伝達物質を送り交える場所です。
神経伝達物質は重要でなぜですか?
-神経伝達物質は思考、感情、記憶など、すべての精神的現象を引き起こすための重要な物質です。
脳にはどのような種類の神経伝達物質が存在しますか?
-脳には30から100種類の神経伝達物質が存在し、そのうち約10種類が脳の99%の機能を担当しています。
アセチルコリンという神経伝達物質は何に関与していますか?
-アセチルコリンは自発的運動と記憶に関与し、アルツハイマー病や黒寡婦クモの毒に関連しています。
ドーパミンはどのような役割を果たしていますか?
-ドーパミンは運動、警醒感に関与し、コカインなどのドラッグはドーパミンレベルを上昇させ、過剰なドーパミンはスチゾフレンニアに関連しています。
セロトニンはどのように人体健康に影響していますか?
-セロトニンは気分のコントロールに関わり、不足するとclinical depressionに陥る可能性があります。抗うつ薬はセロトニンレベルを上昇させることでうつを緩和する効果があります。
エンドルフィンはどのような役割を果たしていますか?
-エンドルフィンは痛みを制御し、ランニングハイの原因とも言われています。また、ヘロインなどのオピオイドはエンドルフィンの働きを模倣します。
神経伝達物質がどのようにニューロン間を移動するのですか?
-ニューロンがアクションポテンシャルを起こすと、アキソン末端から神経伝達物質がシナプスを介して次のニューロンのデンドライトに放出され、そのニューロンがアクションポテンシャルを起こす準備が整います。
薬物は神経伝達物質とどのように関係していますか?
-薬物は神経伝達物質を模倣したり、ブロックしたり、再吸収を妨げたりして作用します。これにより、特定の精神的効果を引き起こします。
Outlines
🧠 思考はどこから来るのか
この段落では、思考がどのようにして生み出されるかについて説明しています。まず、思考は脳からの物であり、特に神経細胞(ニューロン)からの物であると述べています。ニューロンは約1000億個あり、それらが互いに通信することで思考や感情、記憶が生み出されますが、ニューロン同士は決して触れ合わず、その間のギャップ(シナプス)を神経伝達物質(ニューロトランジター)が埋めています。重要なニューロトランジターにはアセチルコリン、ドーパミン、セロトニン、エンドルフィンなどがあり、これらは運動、記憶、気分のコントロールに関与しています。さらに、これらのニューロトランジターの不均衡はアルツハイマー病やパーキンソン病、うつ病に関連しているとされています。
🔬 ニューロンの構造とニューロトランジターの放出
この段落では、ニューロンの構造と神経伝達物質がどのようにしてニューロン間を移動するかについて説明しています。デンドライトはニューロトランジターを捕捉し、それによりニューロンはシナプスを越えて通信します。ニューロンの本体の部分であるソマは、デンドライトから受けた刺激を集約し、アクションポテンシャルを引き起こす閾値に達すると、アクソン(ニューロンの長い突起)が電気的信号を送り出します。アクソンの先端にある終末ボタンは、放出されるニューロトランジターを蓄えています。アクションポテンシャルが終末ボタンに達すると、ニューロトランジターがシナプスを越えて次のニューロンのデンドライトに放出され、そのプロセスが次のニューロンでも繰り返されます。使用されなかったニューロトランジターは再吸収され、このバランスが精神の健康に関連しています。
💊 薬物とニューロトランジターの関係
最後の段落では、薬物がニューロトランジターを模倣したり阻害することで、どのようにして精神的効果を引き起こすかについて説明しています。薬物はアゴニスト(ニューロトランジターを模倣するもの)、アンタゴニスト(ニューロトランジターの働きを妨げるもの)、リウプタケ阻害剤(使用されなかったニューロトランジターの再吸収を妨げるもの)の3つのカテゴリに分けられます。例えば、コカインはドーパミンのリウプタケを阻害し、シナプス内にドーパミンが余り続けることで高揚感を引き起こします。一方で、抗うつ薬はセロトニンのリウプタケを阻害し、うつ病の緩和を目指します。このセクションでは、ニューロトランジターと薬物が精神的機能に与える影響について簡単に説明しています。
Mindmap
Keywords
💡ニューロン
💡シナプス
💡神経伝達物質
💡アセチルコリン
💡ドーパミン
💡セロトニン
💡エンドルフィン
💡デンドライト
💡ソマ
💡アキオン
💡アクションポテンシャル
💡リウプタケ
Highlights
Thoughts originate from the brain, specifically from neurons.
There are approximately 100 billion neurons in the human brain.
Neurons communicate with each other without touching, across a gap called the synapse.
Neurotransmitters are chemicals that neurons use to communicate across the synapse.
Neurotransmitters are responsible for every thought, feeling, emotion, and memory.
There are between 30 and 100 types of neurotransmitters, with about 10 handling most functions.
Acetylcholine is a neurotransmitter involved in voluntary motor movement and memory.
Dopamine is associated with motor movement, alertness, and is affected by drugs like cocaine.
Serotonin is linked to mood control and a lack of it can be associated with clinical depression.
Endorphins are neurotransmitters that deal with pain control and the 'runner's high'.
Norepinephrine is involved in alertness and arousal, and a lack can lead to depression.
GABA is a neurotransmitter that deals with sleep issues.
The structure of a neuron includes dendrites, soma, axon, and terminal buttons.
Dendrites receive neurotransmitters and, when enough is received, trigger the neuron to fire.
The axon is responsible for sending electrical messages and is insulated by the myelin sheath.
Terminal buttons store and release neurotransmitters across the synapse.
Neurons have a resting potential with a negative charge until they reach threshold.
The all-or-none response describes the neuron's decision to fire or not.
Drugs can mimic or block neurotransmitters, or inhibit their reuptake.
Cocaine is a dopamine reuptake inhibitor, leading to increased dopamine levels and the 'high' feeling.
Antidepressants like SSRIs are reuptake inhibitors for serotonin, potentially alleviating depression.
Transcripts
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]
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