load_proc("nrnmainmenu")
load_file("nrngui.hoc")
access soma
area(0.5)
distance()
proc geom_nseg() {
soma area(0.5) // make sure diam reflects 3d points
forall {nseg = int((L/(0.1*lambda_f(10000))+0.9)/2)*2+1}
}
//--------------------------------------------------------------
// Initialise user-defined membrane parameters
// --------------------------------------------------------------
proc parameters() {
celsius = 33
Ri = 80
Cm = 1.0
Rm = 15000
v_init = -85
Spinescale = 1.5
}
// ----------------------------------------------------------------------------
// Channel densities
//-----------------------------------------------------------------------------
//CAVE: check for parameter-settings in loaded sessions
na_ais = 7000
na_node = 7000
na_collat = 500
na_soma = 500
na_dend = 20
na_myelin = 40
max_distance_apic = 300 // distance where gbar_na has reached na_dend
max_distance_basal = 100 //corresponding distance for basal dendrites
vShift_na = 10 // affecting activation and inactivation
vShift_inact_na = 10 // affects only inactivation
q10_na = 3
q10h_na = 3
vShift_nax = 10
vShift_inact_nax = 10
q10_nax = 3.0
q10h_nax = 3.0
length_constant_Kv_and_Kv1 = 80 //length constant of the exponential decay in um of Kv and Kv1
//according to Keren et al., 2009, JPhysiol, 587:1413-37
Kv_soma = 100
Kv_dend = 3
Kv1_dend = 0.3
Kv1_ais = 2000
Kv1_soma = 100
Kv1_collat = 400
vShift_Kv1 = 10
vShift_inact_Kv1 = -15
Kv7_soma = 1
Kv7_dend = 1
Kv7_ais = 7
ca_reduce_fac = 0.1
gca_dend = 2.0*ca_reduce_fac
gca_soma = 2.0*ca_reduce_fac
gca_ais = 0.0
git2_ais = 0.0
git2_dend = 2.0*ca_reduce_fac
git2_apic = 6.0*ca_reduce_fac
git2_soma = 2.0*ca_reduce_fac
gkca_soma = 1.0*ca_reduce_fac
gkca_dend = 1.0*ca_reduce_fac
gkca_ais = 1.0*ca_reduce_fac
gCa_HVA_apic_hot_fac= 1 //i.e. no Ca hot spot //ca
gCa_LVAst_apic_hot_fac= 1 //it2
gCa_hot_start = 685
gCa_hot_end = 885
spinescale = 1.5
sheaths = 10 //number of myelin sheaths
// ----------------------------------------------------------------------------
// Initialisation of passive and active properties, spine scaling, Rm and Cm
//-----------------------------------------------------------------------------
proc init_channels() {
//all
forall {
insert pas
Ra=Ri
e_pas=v_init
g_pas=1/Rm
cm=Cm
}
// dendrites
for i=0,dendNum-1 {
dend[i] {
g_pas=1/(Rm/spinescale)
cm=Cm*spinescale
insert na //gbar_na=na_dend*spinescale //see below
insert Kv gbar_Kv=Kv_dend*spinescale //see below
insert Kv7 gbar_Kv7=Kv7_dend
insert kca gbar_kca = gkca_dend*spinescale
insert cad
insert ca gbar_ca = gca_dend*spinescale
insert it2 gcabar_it2 = git2_dend*spinescale
insert Kv1 gbar_Kv1 = Kv1_dend
}
}
for i=0,apicNum-1 {
apic[i] {
g_pas=1/(Rm/spinescale)
cm=Cm*spinescale
insert na //gbar_na=na_dend*spinescale //see below
insert Kv gbar_Kv=Kv_dend*spinescale //see below
insert Kv7 gbar_Kv7=Kv7_soma
insert kca gbar_kca = gkca_dend*spinescale
insert cad
insert ca gbar_ca = gca_dend*spinescale
insert it2 gcabar_it2 = git2_apic*spinescale
insert Kv1 gbar_Kv1 = Kv1_dend
}
}
//soma
soma {nseg=9}
soma {
insert na gbar_na = na_soma
insert Kv gbar_Kv = Kv_soma
insert ca gbar_ca = gca_soma
insert kca gbar_kca = gkca_soma
insert cad
insert it2 gcabar_it2 = git2_dend
insert Kv7 gbar_Kv7 = Kv7_soma
insert Kv1 gbar_Kv1 = Kv1_soma
}
//collaterals note that axon[0] is AIS
for i=1,axonNum-1 {
axon[i] {
g_pas=1/Rm
insert nax gbar_nax = na_collat
insert Kv1 gbar_Kv1 = Kv1_collat
}
}
//AIS
axon[0] {
nseg=21
insert nax gbar_nax(0:0.4) = 0:na_ais
gbar_nax(0.4:1) = na_ais:na_ais
insert na gbar_na(0:0.2) = na_soma:5000
gbar_na(0.2:0.4) = 5000:0
insert Kv1 axon.gbar_Kv1(0:1)= Kv1_soma:Kv1_ais
insert Kv7 axon.gbar_Kv7(0:0.4) = Kv7_soma:Kv7_soma
axon.gbar_Kv7(0.4:1) = Kv7_soma:Kv7_ais
insert cad
insert ca gbar_ca = gca_ais
insert it2 gcabar_it2 = git2_ais
insert kca gbar_kca = gkca_ais
}
//main axon: i.e. myelin and nodes
for i=0,myNum-1 {
my[i] {
g_pas=1/(Rm * (sheaths + 1))
cm=Cm/(sheaths + 1)
insert nax gbar_nax = na_myelin
insert Kv7 gbar_Kv7 = Kv7_soma
insert Kv1 gbar_Kv1 = 20
}
}
for i=0,myNum-1 {
node[i] {
g_pas=1/Rm
insert nax gbar_nax = na_node
insert Kv1 gbar_Kv1 = Kv1_ais
insert Kv7 gbar_Kv7 = Kv7_ais
}
}
forall ena=55
forall ek=-98
forall insert charge_
// ---------------------------------------------------------------------
// Calcium enhancement to reproduce frequency effect (Larkum et al,1999)
// ----------------------------------------------------------------------
forall {
vh1_it2 = 56
vh2_it2 = 415
ah_it2 = 30
v12m_it2 = 45
v12h_it2 = 65
am_it2 = 3
vshift_it2 = 10
vm1_it2 = 50
vm2_it2 = 125
}
forall if(ismembrane("ca_ion")) {
eca = 140
ion_style("ca_ion",0,1,0,0,0)
vshift_ca = 8
}
forall {
caix_kca = 0.7 // Ca-sensitivity of Kca channel
Ra_kca = 1 // Activation rate Kca
Rb_kca = 2.5 // inactivation rate Kca, important !
taur_cad = 80 // Calcium extrusion rate, in ms
}
//possibility to implement hot-zone
access soma
area(0.5)
distance()
//apical dendrites
for i=0,apicNum-1 {
apic[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
if(distance(pos) > gCa_hot_start && distance(pos) < gCa_hot_end) {
gbar_ca(pos) = gca_dend*gCa_HVA_apic_hot_fac*spinescale
gcabar_it2(pos) = git2_apic*gCa_LVAst_apic_hot_fac*spinescale
}
}
}
}
// --------------------------------------------------------------------------
// Dendritic exponential distribution of Ih (Kole et al., 2006)
// --------------------------------------------------------------------------
A = 0.0002 //0.000429 before, and also the J Neurosci value I aim for a ~20 Mohm input resistance
tau = 0.003087
spinescale = 1.5
forall {
insert ih
gh_ih=-0.0002
eh_ih=-45
}
access soma
area(0.5)
distance()
//basal dendrites
for i=0,dendNum-1 {
dend[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
gbar_ih(pos)=(gh_ih+(A*(exp(tau*distance(pos)))))*spinescale
}
}
}
//apical dendrites
for i=0,apicNum-1 {
apic[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
gbar_ih(pos)=(gh_ih+(A*(exp(tau*distance(pos)))))*spinescale
}
}
}
soma {gbar_ih = 0.0002}
for i=1,axonNum-1 {
axon[i] {gbar_ih=0.0005}
}
// --------------------------------------------------------------------------
// Dendritic linear distribution of na (Keren et al., 2009, JPhysiol, 587:1413-37)
// --------------------------------------------------------------------------
access soma
area(0.5)
distance()
//basal dendrites
for i=0,dendNum-1 {
dend[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
if (distance(pos) >= max_distance_basal) {
gbar_na(pos)=na_dend*spinescale
} else {
gbar_na(pos)=(na_dend+(na_soma-na_dend)*(1-(distance(pos)/max_distance_basal)))*spinescale
}
}
}
}
//apical dendrites
for i=0,apicNum-1 {
apic[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
if (distance(pos) >= max_distance_apic) {
gbar_na(pos)=na_dend*spinescale
} else {
gbar_na(pos)=(na_dend+(na_soma-na_dend)*(1-(distance(pos)/max_distance_apic)))*spinescale
}
}
}
}
// --------------------------------------------------------------------------
// Dendritic linear distribution of Kv and Kv1 (Keren et al., 2009, JPhysiol, 587:1413-37)
// --------------------------------------------------------------------------
access soma
area(0.5)
distance()
//basal dendrites
for i=0,dendNum-1 {
dend[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
gbar_Kv(pos)=(Kv_dend+(Kv_soma-Kv_dend)*exp(-distance(pos)/length_constant_Kv_and_Kv1))*spinescale
gbar_Kv1(pos)=(Kv1_dend+(Kv1_soma-Kv1_dend)*exp(-distance(pos)/length_constant_Kv_and_Kv1))*spinescale
}
}
}
//apical dendrites
for i=0,apicNum-1 {
apic[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
gbar_Kv(pos)=(Kv_dend+(Kv_soma-Kv_dend)*exp(-distance(pos)/length_constant_Kv_and_Kv1))*spinescale
gbar_Kv1(pos)=(Kv1_dend+(Kv1_soma-Kv1_dend)*exp(-distance(pos)/length_constant_Kv_and_Kv1))*spinescale
}
}
}
}
proc testAp() {
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "--------------------------------------------------------- A P I C ---------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
for i=0,apicNum-1 {
apic[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
print " i ",i, " nseg ", j, " pos ",pos, " distance(pos) ",distance(pos)
print " gbar_ih ", gbar_ih(pos), " gbar_na ", gbar_na(pos), " gbar_Kv ", gbar_Kv(pos), " gbar_Kv1 ", gbar_Kv1(pos)
}
}
}
}
proc testBa() {
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "--------------------------------------------------------- B A S A L -------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
print "-----------------------------------------------------------------------------------------------------------------------------------------------------------"
for i=0,dendNum-1 {
dend[i] {
for j=1,nseg {
pos=0.5/nseg+(j-1)/nseg
print " i ",i, " nseg ", j, " pos ",pos, " distance(pos) ",distance(pos)
print " gbar_ih ", gbar_ih(pos), " gbar_na ", gbar_na(pos), " gbar_Kv ", gbar_Kv(pos), " gbar_Kv1 ", gbar_Kv1(pos)
}
}
}
}