load_file("nrngui.hoc")
nmyl = 1
create soma, dend, is, myelin[nmyl], node[nmyl], extra
access soma
objref ax, somden
ax = new SectionList()
forsec "node" ax.append()
is ax.append()
extra ax.append()
somden = new SectionList()
soma somden.append
dend somden.append
connect dend(0), soma(1)
connect is(0), soma(0)
connect myelin[0](0), is(1)
for i=0, nmyl-2 {
connect node[i](0), myelin[i](1)
connect myelin[i+1](0), node[i](1)
}
connect node[nmyl-1](0), myelin[nmyl-1](1)
connect extra(0) , node[nmyl-1](1)
// "extra" is a bit of unmyelinated axon for stimulating purposes
forall { Ra = 100 insert dc }
forsec ax shift_dc = -10
dend { nseg = 30 cm = 1 }
soma { nseg = 6 cm = 1 }
is { nseg = 5 cm = 1 }
forsec "myelin" { nseg = 5 cm = .05 }
forsec "node" { nseg = 1 cm = 1 }
extra { nseg = 10 cm = 1 }
// relative to rest of 0 mV
vrest_dc = 0
forall {ena = 115 ek = -5 el_dc = 0 }
dend { diam=2*30 L=4500 gnabar_dc=0 gkbar_dc=0 gl_dc=.167e-3 }
soma { diam=2*30 L=300 gnabar_dc=.07 gkbar_dc=.0175 gl_dc=.167e-3 }
is { diam=2*5 L=100 gnabar_dc=.6 gkbar_dc=.1 gl_dc=1e-3 }
forsec "myelin" { diam=2*8 L=400 gnabar_dc=0 gkbar_dc=0 gl_dc=.05e-3 }
forsec "node" { diam=2*10 L=75 gnabar_dc=.6 gkbar_dc=.1 gl_dc=3e-3 }
extra { diam=2*5 L=500 gnabar_dc=.07 gkbar_dc=.0175 gl_dc=.167e-3 }
proc init() {
finitialize(v_init)
fcurrent()
}
// use following for exact resting potential of 0
/*
proc init() {
finitialize(v_init)
fcurrent()
forall {
el_dc = (ina + ik)/gl_dc + v
}
}
*/