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Kdr.mod
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Kdr.mod
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TITLE Delayed rectifire
COMMENT
from "An Active Membrane Model of the Cerebellar Purkinje Cell
1. Simulation of Current Clamp in Slice"
ENDCOMMENT
UNITS {
(mA) = (milliamp)
(mV) = (millivolt)
}
NEURON {
SUFFIX Kdr
USEION k WRITE ik
RANGE gkbar, gk, minf, hinf, mexp, hexp, ik, alpha, beta
}
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
PARAMETER {
v (mV)
celsius = 37 (degC)
dt (ms)
gkbar = .6 (mho/cm2)
ek = -85 (mV)
}
STATE {
m h
}
ASSIGNED {
ik (mA/cm2)
gk minf hinf mexp hexp
}
BREAKPOINT {
SOLVE states
gk = gkbar *m*m*h
ik = gk* (v-ek)
}
UNITSOFF
INITIAL {
rates(v)
m = minf
h = hinf
}
PROCEDURE states() { :Computes state variables m,h
rates(v) : at the current v and dt.
m = m + mexp*(minf-m)
h = h + hexp*(hinf-h)
}
PROCEDURE rates(v) { :Computes rate and other constants at current v.
:Call once from HOC to initialize inf at resting v.
LOCAL q10, tinc, tauh, alpha, beta, gamma, zeta, taum
: TABLE minf, mexp, hinf, hexp DEPEND dt, celsius FROM -100 TO 100 WITH 2:00
q10 = 3^((celsius - 37)/10)
tinc = -dt * q10
:"m" potassium activation system
alpha = -0.0047*(v-8)/(exp((v-8)/(-12))-0.9999)
: if(v == 8) {v = 8.0001}
beta = exp((v+127)/(-30))
minf = alpha/(alpha+beta)
gamma = -0.0047*(v+12)/(exp((v+12)/(-12))-0.9999)
zeta = exp((v+147)/(-30))
taum = 1/(gamma + zeta)
mexp = 1 - exp(tinc/taum)
:"h" potassium activation system
hinf = 1.0 / (1+exp((v+25)/4))
if(v<-25) {
tauh = 1200
}else{
tauh = 10
}
hexp = 1 - exp(tinc/tauh)
}
UNITSON