// this file contains procedures used to set the membrane properties
limit=0.05
proc init_params() {
// initialize user-defined membrane parameters
celsius = 35
global_ra = 139.09 // internal resistivity in ohm-cm
Cm = 1.70944 // specific membrane capacitance in uF/cm^2
Rn = 50 // nodal resistivity
Vleak = -50 // leak reversal in Control
Vrest = -60 // resting potential -63 in control
target = 59.42 // input resistance target in CsCl
gnabarmax = 0.05
gnabarmin = 0.05
distslowfrac = 1
gca = 0.000
isegfactor = 10
isegfrac = 0.8
kascale = 1.0
hscale = 1.0
basalfrac=0.6
// attenuation is 0.515 in CsCl for this cell
// passive membrane parameters determined by fitting Cs data
// nonuniform Rm values and nonuniform gh
global_ra = 117.15
rmsoma = 2.8201e+05
rmend = 33938
rmhalfdis = 186.04
rmsteep = 31.681
Cm = 1.5657
Vrest = -63
minq = 0.038794
//maxq = 162.77
maxq = 20
qhalfdis = 316.65
qsteep = 20.001
erevh_h = -25
zeta_h = 10.917
a0_h = 0.00028504
qten_h = 4.5
// Active properties start here
// User-defined properties for K(A) current
gkap = 0.1
gkad = 0.1
gkaaxon = 0.05
gkanode = gkap * 0.2
dlimit = 450
dprox = 100
dslope = 0.005
// User-defined properties for Kdr current
gkdr = 0.1
gkdrsoma=gkdr
// User-defined properties for Na current
gnabar = 0
gnanode = 1 // conductance for sodium at node
nalimit = 275 // cut-off limit for increase of sodium conductance
naslope = 0.00 // slope of sodium channel density
}
proc insert_pass() {
// insert and initialize membrane properties
forsec all_dendrites {
insert pas
Ra = global_ra
e_pas = Vleak
}
print "Inserting spines and setting spine scale values"
forall {insert spines scale_spines = 1.0}
forsec all_dendrites { insert spines scale_spines=1.0 }
forsec no_spines { scale_spines = 1.0 }
forsec basals { scale_spines = 2.7 }
forsec med_spines_rad { scale_spines = 1.2 }
forsec max_spines_rad { scale_spines = 1.6 }
forsec thin_rad { scale_spines = 2.6 }
forsec med_spines_LM { scale_spines = 1.1 }
forsec thin_LM { scale_spines = 1.2 }
init_pass2(Cm) // initialize nonuniform passive membrane
print "Inserting nonuniform passive membrane"
printf("rmsoma = %3.0f, rmend = %3.0f, rmsteep = %3.0f\n",rmsoma, rmend, rmsteep)
}
proc insert_h() {
printf("Inserting sag conductance in all segments\n")
forsec all_dendrites {
insert h
gbar_h = 0
}
init_h5(a0_h*1000) // initialize nonuniform Rm, nonuniform Ih
}
proc insert_ka() {
printf("Inserting K(A) conductance in all segments\n")
forall {
insert kap
insert kad
gbar_kap = 0
gbar_kad = 0
}
init_ka()
}
proc insert_kdr() {
printf("Inserting Kdr conductance in all segments\n")
forall {
insert kdr
gbar_kdr = 0
}
init_kdr()
}
proc insert_na() {
printf("Inserting Na conductance in all segments\n")
forall {
insert naslowcond2
insert nafast2
}
init_na()
}
proc init_pass2() {
// Initialize parameters for nonuniform Rm
// sigmoidal decrease in Rm from rmsoma to rmend
// rmsoma and rmend, and rmhalfdis and rmsteep are set in init_params
// function applies to basal dendrites also
Cm = $1
soma.sec distance()
forsec all_dendrites {
for (x) {
dis = distance(x)
rmpoint = rmend + (rmsoma - rmend)/(1 + exp((dis - rmhalfdis)/rmsteep))
g_pas(x) = 1/(rmpoint/scale_spines)
}
cm = Cm * scale_spines
Ra = global_ra
}
hill {
insert pas
cm = Cm
for (x) {
dis = distance(x)
rmpoint = rmend + (rmsoma - rmend)/(1 + exp((dis - rmhalfdis)/rmsteep))
g_pas(x) = 1/(rmpoint/scale_spines)
}
}
iseg {
insert pas
cm = Cm
for (x) {
dis = distance(x)
rmpoint = rmend + (rmsoma - rmend)/(1 + exp((dis - rmhalfdis)/rmsteep))
g_pas(x) = 1/(rmpoint/scale_spines)
}
}
for i = 0,2 inode[i] {
insert pas
cm = Cm
for (x) {
dis = distance(x)
rmpoint = rmend + (rmsoma - rmend)/(1 + exp((dis - rmhalfdis)/rmsteep))
g_pas(x) = 1/(rmpoint/scale_spines)
}
}
for i = 0,1 node[i] {
insert pas
cm = Cm
for (x) {
insert pas
dis = distance(x)
rmpoint = rmend + (rmsoma - rmend)/(1 + exp((dis - rmhalfdis)/rmsteep))
g_pas(x) = 1/(rmpoint/scale_spines)
}
}
}
proc init_h5() {
// Initialize nonuniform H conductance
// scale up sag conductance as a sigmoidal function of distance from the soma
// q = minq+(maxq-minq)/(1+exp((-dis-qhalfdis)/qsteep))
// basals are set to the same value as the soma
// set minq, maxq, and qhalfdis and qsteep in init_params
a0_h = $1/1000
soma.sec distance()
forsec all_dendrites {
for (x) {
dis = distance(x)
hpoint = minq + (maxq - minq)/(1 + exp(-(dis - qhalfdis)/qsteep))
gbar_h(x) = hpoint * scale_spines
}
}
soma.sec distance()
forsec basals {
for (x) {
gbar_h(x) = minq * scale_spines
}
}
}
proc init_kdr() {
// Initialize parameters for Kdr channels
forall {
gbar_kdr = gkdr
}
soma.sec distance()
forsec new_basals {
for (x) {
xdist=distance(x)
kdrfrac=(1-xdist*dslopebasal)
if (kdrfrac < limit) {
kdrfrac = limit
}
gbar_kdr(x)=gkdr*1.4*kdrfrac
}
}
}
proc init_na() {
// Initialize parameters for Na channels
nalimit = 300
naslope = (gnabarmin-gnabarmax)/nalimit
soma.sec distance()
somaA {
gbar_nafast2 = gnabarmax
gbar_naslowcond2 = 0
}
forsec new_basals {
for (x) {
xdist=distance(x)
nafrac=(1-xdist*naslopebasal)
if (nafrac < limit) {
nafrac = limit
}
gbar_nafast2(x)=gnabarmax*nafrac*basalfrac
gbar_naslowcond2 = 0
}
}
forsec apicals {
for (x) {
xdist = distance(x)
if (xdist>nalimit) {
xdist=nalimit
}
gbar_nafast2(x)=(gnabarmax+(xdist*naslope))*(1-(distslowfrac*(xdist/nalimit)))
gbar_naslowcond2(x)=(gnabarmax+(xdist*naslope))-gbar_nafast2(x)
}
}
hill {
gbar_nafast2= gnabarmax
gbar_naslowcond2 = 0
}
iseg {
for (x) {
gbar_nafast2(x) = 0
if (x < isegfrac) {
gbar_nafast2(x) = gnabarmax
} else {
gbar_nafast2(x) = isegfactor * gnabarmax
}
}
}
for i = 0,2 inode[i] {
gbar_nafast2 = gnabar
}
for i = 0,1 node[i] {
gbar_nafast2 = gnanode
}
}
proc init_ka() {
// Initialize parameters for K(A) channels
soma.sec distance()
somaA {
gbar_kap = gkap * kascale
}
forsec new_basals {
for (x) {
xdist=distance(x)
kafrac=(1-xdist*dslopebasal)
if (kafrac < limit) {
kafrac = limit
}
gbar_kap(x)=gkap*1.4*kafrac*kascale
}
}
forsec apicals {
for (x) {
xdist = distance(x)
if (xdist > dlimit) {
xdist = dlimit
}
if (x!=1) {
gbar_kap(x) = 0
gbar_kad(x) = 0
if (xdist > dprox) {
gbar_kad(x) = gkad * (1 + xdist * dslope) * kascale
} else {
gbar_kap(x) = gkap * (1 + xdist * dslope) * kascale
}
}
}
}
hill {
gbar_kdr = gkaaxon
}
iseg {
gbar_kdr = gkaaxon
}
for i = 0,2 inode[i] {
gbar_kdr = gkaaxon
}
for i = 0,1 node[i] {
gbar_kdr = gkaaxon * 0.2
}
}
proc init_props() {
insert_h()
insert_kdr()
insert_na()
insert_ka()
}
proc reinit_props() {
k = 0
init_pass2(Cm) // initialize nonuniform passive membrane
init_h5(a0_h*1000) // initialize nonuniform Rm, nonuniform Ih
init_kdr()
init_ka()
init_na()
}
| 
