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How to calculate Cell's Total Capacitance (not cm)?

Posted: Wed Jan 18, 2012 12:59 am
Hi,

I am interested in knowing about the calculation of cell's total capacitance (not specific membrane capacitance (cm)). Under the biophysical properties of a section, cm is specified but I wanted to know the calculation of total membrane capacitance.

Could you kindly let me know how to do this? As I am a learner, detailed explanation could be very helpful.

Re: How to calculate Cell's Total Capacitance (not cm)?

Posted: Wed Jan 18, 2012 1:14 am
Good question. In pseudocode the algorithm would be

Code: Select all

``````cmtotal = 0
for each section
for each segment
cmtotal += segment_area * segment_cm``````
In hoc I'd implement this as a function

Code: Select all

``````func totalcm() { local tmp
tmp = 0
forall for (x,0) tmp += area(x)*cm(x)
return tmp
}``````
The NEURON Programmer's Reference contains informative entries about the following:
func
local variables in functions
forall
for (x,0) and for (x)
area()
cm
syntax
expression

"Why did your pseudocode use a variable called cmtotal, but your function used a different name?"
No reason, actually.

Re: How to calculate Cell's Total Capacitance (not cm)?

Posted: Wed Jan 18, 2012 3:15 am
Thank you Ted for the quick reply.

Re: How to calculate Cell's Total Capacitance (not cm)?

Posted: Wed Jan 18, 2012 9:25 am
Thanks for using NEURON in your research, and also for asking a question whose answer will, in one way or another, probably be of interest to many other users.