I have just begun to learn to use NEURON and read the Extracellular Stimulation and Recording program downloaded from http://www.neuron.yale.edu/ftp/ted/neur ... nd_rec.zip
. Now I have six very primary questions:
1 nesg is decided by d_lambda rule. In other words nesg=int((L/(0.1*lambda_f(100))+0.9)/2)*2+1. Could you please tell me how to derive this equation?
2 lambda_f=(1/2)square(d/(pi*f*Ra*Cm)). Where does this equation come from?
3 In calcrxc.hoc, the resistance outside the sphere electrode with radius r0 can be calculated as follows.
Therefore the resistance between r1 and r0 should beA conductive sphere of radius r0 is suspended in an infinite
volume of solution that has resistivity rho [ohm cm]. Ignoring
electrochemical effects at the electrode|solution interface,
what is the resistance between the surface of the sphere and
an infinitely distant ground electrode?
The surface area of a sphere with radius r is 4 PI r^2.
The resistance of a shell with thickness dr is
rho dr / 4 PI r^2
and the resistance is therefore
inf
INTEGRAL rho dr / 4 PI r^2
r0
inf
= - rho / 4 PI r | = rho / 4 PI r0
r0
r1
INTEGRAL rho dr / (4 PI r^2)
r0
r1
=( - rho / 4 PI r |) = -rho / (4 PI r1)+rho /( 4 PI r0)
r0
where r1 is the distance from the center of the electrode.
so,why
4 The statement “for(x) ……â€to a first approximation, a monopolar stimulating electrode
that delivers current I produces a field in which potential V
is given by
V = I rho / (4 PI r)
where r is the distance from the center of the electrode