I am trying to develop a simple axon model that represents nodes of Ranvier connected by "perfectly insulating" myelinated internodal segments. Sweeney channel mechanics are used at the nodes (sodium and leakage currents). I would like to apply stimulation to this model using the extracellular mechanism, with the extracellular potentials at the nodes of Ranvier calculated through interpolation within a FEM program (ANSYS Ansoft). Since the internodal myelinated segments are perfectly insulating, I did not add any channel mechanics or transmembrane capacitance to these segments, nor did I apply a non-zero extracellular voltage. My procedure code for creating such an axon is below:
Code: Select all
proc create_axon(){
for i=0, Nnodes-1 {
node[i]{
nseg=1
diam=Dnode
L=Lnode
Ra=rhoa
cm=Cm
insert sw //sweeney channel mechanics//
ena = 35.64
insert extracellular xraxial=1e9 xg=1e9 xc=0
}
}
for i=0, Nnodes-2 {
internode[i] {
nseg=1
diam=Dinter
L=Linter
Ra=rhoa
cm=0
insert extracellular xraxial=1e9 xg=1e9 xc=0 e_extracellular=0
}
}
//connect nodes//
for i=0, Nnodes-2 {
connect node[i](1), internode[i](0)
connect internode[i](1), node[i+1](0)
}
}
Much appreciated.