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

[Krishna Chaitanya]

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.

[ted]

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.

[Krishna Chaitanya]

Thank you Ted for the quick reply.

[ted]

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.