Hi,
I am working on a multicompartment model and need to find out the magnitude of current flowing from one compartment to another. I am having nseg = 1 for now for all compartments. I am using the formula ((Vsoma(0.5)Vdend[0](0.5))/((2Rasoma*Lsoma/(pi * Dsoma^2))+(2Radend*Ldend/(pi * Ddend^2))) to plot the current. Is there an easier way to calculate this in neuron. I need to do that for all the compartments and so wanted to know if neuron has some default function/parameter which does this..
Thanks
Pranit
Calculate current flowing from one compartment to another

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Re: Calculate current flowing from one compartment to anothe
NEURON calculates the time course of membrane potential at points in space that are called nodes. Each section has a node at its 0 and 1 ends, and at nseg evenly spaced internal locations that range from 0.5/nseg to (nseg1+0.5)/nseg, where nseg is the section's discretization parameter.
NEURON has a function called ri() that is useful for what you want. ri(x) returns the resistance between the node at x and its parent. This procedure iterates over all nodes in the currently accessed section to report the axial current between each adjacent pair of nodes in the section.All you have to do is iterate over all sections in your model cell and execute seciax() each time. This oneliner will do it:
NEURON has a function called ri() that is useful for what you want. ri(x) returns the resistance between the node at x and its parent. This procedure iterates over all nodes in the currently accessed section to report the axial current between each adjacent pair of nodes in the section.
Code: Select all
// for each node in current section that has x>0
// report axial current that enters this node from its parent
proc seciax() { local vp, vthis
print secname()
for (x) {
if (x==0) {
vp = v(x)
} else {
vthis = v(x)
print x, (vpvthis)/ri(x)
vp = vthis // prepare to deal with next node
}
}
}
Code: Select all
forall seciax()
Re: Calculate current flowing from one compartment to anothe
Thanks Ted. This was exactly what i was looking for.