// Cat FR motoneuron model (reduced morphology)
//
// This file constructs the equivalent cylinder of the 3D dendritic morphology of cat FR MN (cell 43/5 in Cullheim et al., 1987)
// The reduced model reproduce the passive properties of the full morphology faithfully
// Reduced model passive properties: Rin = 1.38 MOhm, tau(0)=6.8 ms, tau(1) = 1.5 ms (graphical peeling method)
// Experimental data of same MN: Rin = 1.4 MOhm, tau(0)=6.82 ms, tau(1) = 1.57 ms
//
// Sherif Elbasiouny
// 07/01/2009
// modified to have 3 dendrites
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
load_file("nrngui.hoc") // Load Neuron
create soma, is, d1,d2,d3, axonhillock
access soma
objref dend
dend=new SectionList()
d1 dend.append()
d2 dend.append()
d3 dend.append()
// Define anatomical and biophysical properties of each section
soma {
nseg = 2 // 1 compartment
L = 48.8 // [um] length
diam = 48.8 // [um] diameter
insert pas // standard passive current
g_pas = 1/225 // [S/cm^2] conductance for leak current
e_pas = -70.0 // [mV] equilibrium potential for leak
}
is {
nseg = 5 // 5 compartment (changed by RP for better behavior)
L = 30 // [um] length
diam = 3.3 // [um] diameter
insert pas // standard passive current
g_pas = 1/1000 // [S/cm^2] conductance for leak current; changed from 225 by RP
e_pas = -70 // [mV] equilibrium potential for leak
}
axonhillock {
nseg = 11 // 11 compartments
L = 15 // [um] length; changed by RP to reflect Conradi
diam(0:1) = 3.3:13 // [um] diameter increase
insert pas // standard passive current
g_pas = 1/1000 // [S/cm^2] conductance for leak current; changed from 225 by RP
e_pas = -70 // [mV] equilibrium potential for leak
}
forsec dend {
nseg = 10 // 10 compartments
L = 4635 // [um] total length of the equivalent dendrite
diam =19.2 // [um] diameter of the stem
diam(0.3:1) = 19.2:1 // [um] tapering of the distal dendrite
insert pas // standard passive current
g_pas = 1/11000 // [S/cm^2] conductance for leak current
e_pas = -70 // [mV] equilibrium potential for leak
}
forall {
Ra = 70 // [ohm.cm]
cm = 1 // [uf/cm2]
}
// connect model sections
connect is(1), axonhillock(0)
connect axonhillock(1), soma(0)
connect d1(0),1
connect d2(0),1
connect d3(0), 0.5