2.1.1 神经元信息传递_视频在线视频

神经元的传导主要有三种
There are mainly three kinds of transmission of neurons

一种叫突触的传递
one is called synaptic transmission

刚才我们说了神经元有很多的树突
Just now we said that neurons have many dendrites

树突的末端呢都有突触
and there are synapses at the end of dendrites

第一种就是这种通过突触来联系
The first kind is that they are connected by synapses

它是一种化学的传导不是电信号的传导
It is a chemical transmission,not the transmission of electrical signals

所谓化学呢它就会释放一些物质
So-called chemical transmission,it releases some substances

这些物质呢就引起另外一个神经元的突触的电位发生变化
Some substances cause changes in the synaptic potential of another neuron

引起信号传导
causing signal transduction

第二个就是紧密连接的
The second is tight connection

一个神经元和另一个神经元不是通过突触来传递
One neuron and another neuron are not transmitted through synapses

它本来就结合的很紧
They are closely integrated

就可以近似的看成就是一个神经元间呢电信号直接传过来
It can be seen that the achievement is a direct transmission of electrical signals between neurons

第三种是非突触性的化学传导——释放递质
The third is non-synaptic chemical conduction,releasing the transmitter

最后这种也是释放递质 但它没有突触
and finally this is releasing the transmitter,but it has no synapse

我们今天就主要介绍这三类突触是怎么作用的
Today we will focus on how these three types of synapses work

那么第一类 突触传导
So the first type,synaptic transmission

看上面这个图 synaptic transmission
as shown in the figure above, is called synapse

神经元所形成的一个特异化的结构都叫突触 它这个地方是突触
A specific structure formed by neurons is called synapse,which is the synapse

突触呢它既可以连接神经元的胞体直接形成突触 叫轴突
Synapses can connect the cell bodies of neurons directly to form synapses,called axons

它也会和另外的神经元的树突形成突触
hey also form synapses with dendrites of other neurons

它也可以和神经元的轴突形成突触
It can also synapse with the axons of neurons

突触前膜的里面会有这些红点
There are red dots in the presynaptic membrane

我们叫作囊泡 囊泡里面就有神经递质
These are what we call vesicles.There are neurotransmitters in the vesicles

那这些囊泡到突触前膜 把这些神经递质释放出来
These vesicles go to the presynaptic membrane and release these neurotransmitters

这些神经递质呢会影响受体
These neurotransmitters affect the receptors

本身就是蛋白质 它的一个作用就是形成通道
which are proteins themselves.One of their functions is to form channels

这个受体作用到蛋白质呢 这个通道就打开
which are receptors as soon as it acts on proteins,the channel opens

通道打开以后就会让钠离子流进来 钾离子流出去
When the channel opens,sodium ions will flow in and potassium ions will flow out

这样它会形成一个电位变化 电位变化有可能是局部的 就在这一块
so that it will form a potential change.The potential change may be local,just in this area

如果这个电位变化足够大的话 达到阈电位以后呢
If the potential changes sufficiently,after reaching the threshold potential

它会形成动作电位 就到另一个神经元上去传导这个信号
it will form an action potential,which will transmit the signal to another neuron

那么突触前膜包括 这是小泡 突触前膜和突触小泡
The presynaptic membrane consists of vesicles,presynaptic membrane and synaptic vesicles

小泡里面呢有神经递质
There are neurotransmitters in the vesicles

然后这个突触间隙10到30个纳米 也就是0.01到0.03微米
Then the synaptic gap is 10 to 30 nanometers,that is 0.01 to 0.03 microns

后面这一个是突触后膜
The latter one is the postsynaptic membrane

那么我们看这一组示意图更加的清晰
so we can see this group of sketches more clearly

这是突触前膜 这就是整一个突触的结构
This is the presynaptic membrane,which is the structure of the whole synapse

那这里面这些红色的点点呢就是囊泡 囊泡里面包含神经递质
These red dots in this area are vesicles,which contain neurotransmitters

它的作用呢就是 突触前膜外面的钙离子流进来
Its function is to flow in calcium ions outside the presynaptic membrane

流进来以后呢会使里面的这些液体浓度降低
When it comes in,the concentration of these liquids decreases

降低以后呢这些递质这些囊泡呢就往下面流 流到往这个前膜靠近
and when it decreases,the transmitters, the vesicles,flow downward to the front membrane

靠近以后 囊泡包着的这个结构和前膜这个结构是一样的
Closer to the vesicle,the vesicle encapsulates the same structure as the anterior membrane

所以它到了前膜以后会和前膜融成一块 自己变成前膜
so when it reaches the anterior membrane,it melts into the anterior membrane

然后把里面的神经递质呢释放出来
and then releases the neurotransmitters

但释放递质的多少 和它这个钙离子的流进有关
but the amount of neurotransmitters released depends on the inflow of calcium ions

钙离子流的越多 神经递质释放的越多
The more calcium ions flow,the more neurotransmitters are released,

神经递质释放的越多所以在后面那个神经元所引起的动作电位
and the more neurotransmitters are released

引起的电位也就越大
Therefore,the action potential caused by the neuron in the back is larger

动作电位的可能性也就越高
and the possibility of action potential is higher

我们看这里有一个详细的示意图 看黄色的这一圈这一部分
Let's look at a detailed sketch here.Look at this part of the Yellow circle

这个是突触前膜 这中间的是突触间隙
This is the presynaptic membrane.In the middle is the synaptic gap

这后面蓝色的这一圈是突触后膜
The blue circle behind is the postsynaptic membrane

这一个神经元动作电位传过来 动作电位来了以后 会引起钙离子通道打开
When the action potential of this neuron comes,it will cause the calcium channel to open

外面的钙离子流进来
the calcium ion outside will flow in.

钙离子流进来以后 会使液体浓度降低
When the calcium ion flows in,the concentration of the liquid will decrease

粘度降低以后
and the viscosity will decrease

这些囊泡就会动了 往这个下面流
After that, these vesicles will move and flow down.

流到前膜以后呢进行结合
After flowing to the anterior membrane, combining

把这个囊泡释放出来 释放出来之后
releasing the vesicle,after releasing

它这个受体就会把通道打开
the receptor will open the channel,

这些钠离子就流进来 钾离子出去 形成动作电位
these sodium ions will flow in,potassium ions will go out,form action potential

再传导到下一个神经元 那它整个过程大概是这么一个过程
and then transmit to the next neuron,then the whole process is probably such a process