Conductance values in passive mechanism

[mganguly]

Hi

I wanted to know the basis of the values chosen for the default passive mechanism in NEURON ? (g= 0.001 (S/cm2), e=-70 (mV)). This is different from the leak channel parameters in the HH model ( gl=0.0003 (S/cm2) and el= -54.3 (mV)). Is there any mention of it in the NEURON documentation (or the NEURON book ) ?

Mohit

[ted]

Doubtless the numerical value is mentioned. Can you imagine a reason why that value was chosen, or devise a compelling rationale for making a different value the default?

[mganguly]

Hi
I am not sure about this but off the top of my head, the conductance in the passive mechanism consists of the leak conductance from the HH mechanism plus the minor conductance from the movement of non specific ions.

Mohit

[ted]

I was fishing for something more like this: 0.001 S/cm2 * 1 uf/cm2 = 1 ms. These are perfect default values for constructing examples that correspond fairly closely to mathematical explorations of cable properties, in which time and space and model parameters are "normalized" so that mere arithmetic doesn't intrude on the analysis.