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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.

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.

Posted: **Wed Jan 18, 2012 3:15 am**

Thank you Ted for the quick reply.

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.

www.neuron.yale.edu

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

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

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

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

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