how do neural circuits form?

[gib65]

I want to know if I understand enough about how neural circuits form to make a certain claim.

 

First, take a look at this diagram:

 

 

We have neuron A connected to neuron B connected to neuron C... D... E. When neuron A fires, it stimulates neuron B which in turn stimulates neuron C... D... and E. Also, there is a weak connection between neuron A and neuron E, but this connection is too weak for the firing of neuron A to stimulate neuron E. Finally, assume that when neuron A fires, neuron E eventually gets stimulated and at this time neuron A has not yet died down.

 

So here's my question: if neuron A is still firing at the time that neuron E fires, is this a sufficient condition for the connection between neuron A and neuron E to grow stronger? In other words, after so many trials of neuron A stimulating neuron B... C... D... E, will neuron A eventually be able to stimulate neuron E directly? I guess I'm asking how do neural connection get fortified, and the claim I want to make is that the above scenario is how it happens. Can I do this?

[psynapse]

I was thinking that it is possible.

Here's the scenario, when I was learning my times tables, you would have to think of a tactic to figure it out. Eg 3X3= three groups of three, then count 'em up and you are left with 9. But after a little while you just memorize 3X3=9.

 

So I suppose that memorizing them knocks out any thought process as to how you arrive at an answer.

[ParticleOne]

There is no exact rule for how the conscious part of the brain makes the synapse element enhancements. I guess you elude to training and faster communication, but it is more complex than just finding a short-cut, you can be pretty sure that nodes B-C-D have a say in the process and by bypassing these will cause that the same information is not transmitted E as if it took the "long route".

Take a look at http://online.itp.ucsb.edu/online/bblunch/laughlin1/ “Design of a Brain”, it will not give you a direct answer to your question, but still interesting.

[ParticleOne]

Forgot to include this link: http://online.itp.ucsb.edu/online/brain04/brockwell/ "Modeling of neuronal data"

[gib65]

I was thinking that it is possible.

Here's the scenario, when I was learning my times tables, you would have to think of a tactic to figure it out. Eg 3X3= three groups of three, then count 'em up and you are left with 9. But after a little while you just memorize 3X3=9.

 

So I suppose that memorizing them knocks out any thought process as to how you arrive at an answer.

 

That's exactly the kind of phenomena that prompted me to ask this question.

 

Thanks, PO, for the links. I'll have to watch them later when I have the time, but I surely will.

[nettron]

will neuron A eventually be able to stimulate neuron E directly?

 

No, According to your "wiring" diagram the output (axon) from neuron A is connected to the output (axon) of neuron E, according to the liturature modification occurs in the dendritic tree rather than the axons. But I think I know what you are getting at and it appears very similar to a postulate by Donald Hebb.

[gib65]

No, According to your "wiring" diagram the output (axon) from neuron A is connected to the output (axon) of neuron E, according to the liturature modification occurs in the dendritic tree rather than the axons. But I think I know what you are getting at and it appears very similar to a postulate by Donald Hebb.

 

You're right! I goofed up in my diagram. I should have connected neuron A to the head of neuron E, or its dendrites as you said. In any case, yes, the main idea of what I'm asking is similar to Donald Hebb's theory of cell assemblies.

[psynapse]

If the cells didn't connect the way you propose then how do they function after repititious behavoir? The same only faster? That seems a little counter intuitive. This probably has something to do with sleep and dreaming.

[gib65]

This probably has something to do with sleep and dreaming.

 

It does?