: nap.mod is a persistent Na+ current from
: Baker 2005, parameter assignments and formula's from page 854
NEURON {
SUFFIX nap
USEION na READ ena WRITE ina
RANGE gbar,ina
: THREADSAFE
}
UNITS {
(S) = (siemens)
(mV) = (millivolts)
(mA) = (milliamp)
}
CONSTANT {
q10 =2.7
}
PARAMETER {
gbar = 2.2630e-04 :3.7(nS)/1635(um^2)
: ena= 65 (mV)
A_amp = 17.235 (/ms) : A for alpha m persis
B_amp = 27.58 (mV)
C_amp = -11.47 (mV)
A_bmp = 17.235 (/ms) : A for beta m persis
B_bmp = 86.2 (mV)
C_bmp = 19.8 (mV)
}
ASSIGNED {
v (mV) : NEURON provides this
i (mA/cm2)
g (S/cm2)
tau_m (ms)
minf
hinf
ena
ina
qt
}
STATE { m h }
BREAKPOINT {
SOLVE states METHOD cnexp
g = gbar * m^3
ina = g * (v-ena)
}
INITIAL {
qt = q10^((celsius-22 (degC))/10 (degC))
: assume that equilibrium has been reached
m = alpham(v)/(alpham(v)+betam(v))
}
DERIVATIVE states {
rates(v)
m' = (minf - m)/tau_m
}
FUNCTION alpham(Vm (mV)) (/ms) {
alpham=A_amp/(1+exp((Vm+B_amp)/C_amp))
}
FUNCTION betam(Vm (mV)) (/ms) {
betam=A_bmp/(1+exp((Vm+B_bmp)/C_bmp))
}
FUNCTION rates(Vm (mV)) (/ms) {
tau_m = 1.0 / (alpham(Vm) + betam(Vm))/qt
minf = 1.0/(1+exp(-(Vm+66)/5))
}