Rest Membrane Potential

[thats_karlo]

Dear Firends,

A simple question!!!! please help me to undrestand!!!

Could you tell me, how NEURON calculate rest membrane potential?


If we know conductance and reversal potential, Does NEURON use the followig formula(suppose we have leak, na,k currents)

V=(g_na*E_na+g_k*E_k+g_l*E_l)/(g_na+g_k+g_l)

Consider other case; for some ions, reversal potential and conductance are given and for others, permebility and ionic concentartion, in such condition, how NEURON calculate rest membrane potentail?


Thank's in advance

Karlo

[ted]

It doesn't compute resting potential. If you are using the RunControl panel and have not
customized the standard run system, clicking on Init button will set membrane potential to
the value shown in the box next to the Init button, and set all state variables to their steady
state values for that potential. If you click on Init & Run, it does that first, and then solves
the DEs that describe the model as an initiali value problem from that starting point.

If you need to initialize a model to its own resting level, or if you want to force the resting
level for a model to be at a particular membrane potential, you need to write your own
custom initialization code. You can read more about this here:
https://www.neuron.yale.edu/phpBB2/view ... ustom+init

[thats_karlo]

Dear Ted!

Thank's for reply.

for keeping membrane potential at a constant level i use a ICalmp method.
first, i inject a current to reach membrane potential to a specific level,
and after some delay.e,g 500ms, i use other ICamp current, to study
the response of my model.

is it a rigth way? or it may causes some problems(that i don't know?)

Yours,
Karlo

[ted]

first, i inject a current to reach membrane potential to a specific level,
and after some delay.e,g 500ms, i use other ICamp current, to study
the response of my model.

That can work, if the time you wait is long enough (models that have ion accumulation
mechanisms--especially calcium diffusion/pumps--can require very long simulations
to settle). The other drawback is that the results that you are interested in are preceded
by a long interval in which nothing interesting is happening.