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Ask HN: How do neurons not end up in an infinite loop?

5 points by techsin101 ↗ HN
A neuron triggers other neurons, those in turn trigger more neurons, given each neuron connects to 1000s of other neurons then it's reasonable to think some of them connect to neurons that trigger the parent neurons. In programming this would be akin to cyclical dependency causing infinite loop.

So how come brain just doesn't completely lights up, with each neuron stuck infinite loop?

6 comments

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smt88
Why do you assume that they never do?

A friend of mine has severe OCD and OCPD, and his brain very much seems like it's stuck on a loop. I know some autistic people express the same thing.

techsin101
I meant under normal circumstances
smt88
What about getting a song stuck in your head or having a nervous tic?

I'm not sure the concept of an infinite loop even makes sense for a brain's "architecture" anyway.

After millions of years of evolution, there are lots of "errors" that just aren't common at all, so asking why an error isn't "normal" is very presumptive.

[dead] babulus
In general the contribution of an action potential from one neuron is not enough to make the neurons it's connected to also fire. Neurons require relatively synchronized excitatory inputs from a large number of neurons to induce an action potential. There will also be inhibitory inputs from other neurons as well.

Another phenomenon that counters recurrent excitation is lateral inhibition. An excitatory neuron firing will synapse with an inhibitory interneuron nearby. If the interneuron fires it inhibits a great number of neurons in the local vicinity, including the excitatory neurons that just made it fire. It can act to reduce local excitability.