Myocytes and neurones, initiating activity.

[nobahar]

Hello!
Peculiar question. I was hoping that someone, probably with a background in development or neuroscience, could answer this question for me:
The contraction of heart muscles is achievable independently of any 'outside' source because the heart muscles can initiate action potentials themselves.
I could not find anything on any specialised neurons having a similar property, so how is the CNS 'kickstarted'? Action potentials arise in neurons by depolarisation induced by other neurons. So how is the first action potential in the newly developed/developing CNS achieved?
Does it require interaction with the outside environment?, which could generate action potentials that are relayed to the CNS, and from there the signal is simply 'maintained'?
I assume that the brain is always 'on' from the point forward of the first action potential.
As an analogy: If the cardiac myocytes were not able to initiate action potentials independently, it would require an outside source, it could then have some mechanism for maintaining a controlled contraction. This is not of course the case, since the heart is myogenic.; but since neurons do not appear to have this property to initiate action potentials independently, then there must be something to initiate the first action potential, action potentials could then be maintained within the CNS, I suppose.
Does the question make sense?
Admittedly it's a little peculiar!
Thanks in advance.

[zhermes]

That's an interesting question.

Some neurons do initiate action potentials, its not solely from pre-existing ones. Sensory neurons are the best example---they initiate action potentials after being stimulated by numerous methods (pressure, temperature, strain, pH, etc). Additionally all neurons do experience some stochastic excitation, and occasionally an action potential will spring up.

[nobahar]

Thanks for the response zhermes.

That's an interesting question.

Some neurons do initiate action potentials, its not solely from pre-existing ones. Sensory neurons are the best example---they initiate action potentials after being stimulated by numerous methods (pressure, temperature, strain, pH, etc).

This is what I was wondering. Does it require outside stimulation for the nervous system to 'get started'? Without outside stimulation, would there be brain activity? Perhaps there would be basic functions like breathing, etc, but again how is this kick-started? Higher functions might rely on outside stimulation, I guess.

Additionally all neurons do experience some stochastic excitation, and occasionally an action potential will spring up.

I wonder if this is sufficient to induce the brain into organised and regular activity. I do not know where to begin looking for this information, since it's difficult to articulate.

[Vesalius]

That's an interesting question.

Some neurons do initiate action potentials, its not solely from pre-existing ones. Sensory neurons are the best example---they initiate action potentials after being stimulated by numerous methods (pressure, temperature, strain, pH, etc). Additionally all neurons do experience some stochastic excitation, and occasionally an action potential will spring up.

Perhaps the first AP is generated from sensations carried to the brain via the thalamus and reticular formation. Since the thalamus is usually the one maintaining the basal electrical rhythm, I suppose it was the one that initiates it when the CNS first starts functioning. The neuron may have an inherent property to start discharging as soon it is mature, even if only partially(graded potentials). These excitatory potentials then summate each other and generate an AP....kindly correct me if i am mistaken.....:smile: