Why do neurons use chemical electricity rather than electrons?

[MirceaKitsune]

A few days ago I took a better look at how neurons communicate with each other, how a brain network looks like, and what an action potential is. Although some people did a good job at explaining how signals are transmitted across neurons, fully understanding it all is still proving a rather difficult task, as the system is more complex than I initially thought. Until seeing an in-depth explanation, I used to think neutons are connected by a plain conductive material (similar to wires) through which electrons travel, rather than being a chemical process.

 

I know I was wrong now. But there's still one thing I'm confused about: Why? More precisely, why did evolution "prefer" this system? It would seem that neurons sending electrons to each other directly (like electronics) would be both simpler and quicker. Using sodium and potassium, waiting for various gates to open / close and activate / deactivate, etc. feels like something more comlex than needed. But in evolution, something usually happens for a good reason... so this means I'm failing to understand why the existing system is best.

 

Why is the current mechanism of neurons / nerves / muscles, using chemicals and action potentials, better than neurons simply being conductive materials that sent electrons across to each other? Why wouldn't have the other way worked out, and allowed a brain as functional to evolve (first)? Could it allow one at all actually?

Edited May 21, 2014 by MirceaKitsune

[Greg H.]

First, you seem to have a misconception about how evolution works. Evolution doesn't choose the best or most efficient choice out of a basket - evolution is the slow accumulation of random changes that were best suited for a given environment at the time they were expressed.Why are bodies are chemical based probably has a lot to do with the fact that life as we know it most likely arose from a chemical soup. Since evolution will only make use of what's available, it then follows that our bodies would have a chemical signalling system.

[Rilx]

Why is the current mechanism of neurons / nerves / muscles, using chemicals and action potentials, better than neurons simply being conductive materials that sent electrons across to each other? Why wouldn't have the other way worked out, and allowed a brain as functional to evolve (first)? Could it allow one at all actually?

Neurons are switches that work by opening and closing connections to next neurons. If the whole neural network were nothing but wires connected to each other, brains would be like a bunch of chicken wire. Only electrically isolated switches can perform logical operations, i.e. "send electrons across to each other" in a controllable way.

[Moontanman]

A few days ago I took a better look at how neurons communicate with each other, how a brain network looks like, and what an action potential is. Although some people did a good job at explaining how signals are transmitted across neurons, fully understanding it all is still proving a rather difficult task, as the system is more complex than I initially thought. Until seeing an in-depth explanation, I used to think neutons are connected by a plain conductive material (similar to wires) through which electrons travel, rather than being a chemical process.

 

I know I was wrong now. But there's still one thing I'm confused about: Why? More precisely, why did evolution "prefer" this system? It would seem that neurons sending electrons to each other directly (like electronics) would be both simpler and quicker. Using sodium and potassium, waiting for various gates to open / close and activate / deactivate, etc. feels like something more comlex than needed. But in evolution, something usually happens for a good reason... so this means I'm failing to understand why the existing system is best.

 

Why is the current mechanism of neurons / nerves / muscles, using chemicals and action potentials, better than neurons simply being conductive materials that sent electrons across to each other? Why wouldn't have the other way worked out, and allowed a brain as functional to evolve (first)? Could it allow one at all actually?

 

 

I'm not sure that electricity is an accurate way to define the exchange of positive ions between neurons.

Edited May 21, 2014 by Moontanman

[MirceaKitsune]

First, you seem to have a misconception about how evolution works. Evolution doesn't choose the best or most efficient choice out of a basket - evolution is the slow accumulation of random changes that were best suited for a given environment at the time they were expressed.Why are bodies are chemical based probably has a lot to do with the fact that life as we know it most likely arose from a chemical soup. Since evolution will only make use of what's available, it then follows that our bodies would have a chemical signalling system.

 

Yes, that would be a more correct way of putting it. I believe I wanted to refer to the best and most optimal biological systems being the ones that tend to survive and evolve. Then again, if something else that works was there first, it has high chances of staying, even if something better could have theoretically taken place before it and replaced it.

 

Neurons are switches that work by opening and closing connections to next neurons. If the whole neural network were nothing but wires connected to each other, brains would be like a bunch of chicken wire. Only electrically isolated switches can perform logical operations, i.e. "send electrons across to each other" in a controllable way.

 

I didn't wish to refer to neurons being entirely just wires, although I might have done that. Obviously there would still need to be a controlled way of passing signals over, rather than turning the brain network on or off as a whole. Still, would have using direct electrical circuits between neurons been possible too, given they could transmit signals in a similar fashion?

[Rilx]

I didn't wish to refer to neurons being entirely just wires, although I might have done that. Obviously there would still need to be a controlled way of passing signals over, rather than turning the brain network on or off as a whole. Still, would have using direct electrical circuits between neurons been possible too, given they could transmit signals in a similar fashion?

In artificial logical devices like computers, the control problem has been solved by electronically controlled switches (transistors) which means that the system must consist of two separate networks, the operational and the control network. This kind of systems need extensive planning and precise implementation all the way. Even in large electronic systems which consist of several physical devices, signalling between devices have been changed to use light instead of electrons because isolation problems grow too significant.

 

Biological, evolved systems cannot work that way. The control system in the neural network use potential levels of the operational network (if we use the electronic device terminology) to open the neurotransmitter switches. Because single neurons perform all tasks, every new neuron can always join the network and start working, so to say. It doesn't need to know about larger neural schemas.

[MirceaKitsune]

In artificial logical devices like computers, the control problem has been solved by electronically controlled switches (transistors) which means that the system must consist of two separate networks, the operational and the control network. This kind of systems need extensive planning and precise implementation all the way. Even in large electronic systems which consist of several physical devices, signalling between devices have been changed to use light instead of electrons because isolation problems grow too significant.

 

Biological, evolved systems cannot work that way. The control system in the neural network use potential levels of the operational network (if we use the electronic device terminology) to open the neurotransmitter switches. Because single neurons perform all tasks, every new neuron can always join the network and start working, so to say. It doesn't need to know about larger neural schemas.

 

Ok... so evolution couldn't have made such a complex system work that way by itself, because electrical switches can only be produced intentionally by a person rather than also in nature? That explains why neurons which communicate with direct elecric impulses don't exist. Thanks for clarifying.