CAl.mod

: from Migliore mycan2.mod, no deactivation 
: activation gate from Dimitri, tau  midpoint-
: voltage 
: own GHK
: T-dependece from McAllister-Williams 95


UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)

: hier eigene Befehle
        (molar) = (1/liter)
        (mM) = (millimolar)

	F = 96485 (coul)
	R = 8.3134 (joule/degC)
}

PARAMETER {
	v (mV)
	celsius 		(degC)
: Pcalbar=3/10*PcaRestbar
	PcalBar=.00006622 (cm/s)
: was soll ki
	ki=.00002 (mM)
	cai=5.e-5 (mM)
	cao = 10  (mM)
	q10m=11.45
	q10Ampl=2.1
}


NEURON {
	SUFFIX CAl
	USEION ca READ cai,cao WRITE ica
        RANGE PcalBar
        GLOBAL minf,taum
}

STATE {
	m
}

ASSIGNED {
	ica (mA/cm2)
        Pcal  (cm/s) 
        minf
        taum
}

INITIAL {
        rates(v)
        m = minf
}

UNITSOFF
BREAKPOINT {
	LOCAL qAmpl
	
	qAmpl = q10Ampl^((celsius - 21)/10)
	
	SOLVE states METHOD cnexp
	Pcal = qAmpl*PcalBar*m*m*h2(cai)
	ica = Pcal*ghk(v,cai,cao)

}

FUNCTION h2(cai(mM)) {
	h2 = ki/(ki+cai)
}


FUNCTION ghk(v(mV), ci(mM), co(mM)) (mV) {
        LOCAL a

        a=2*F*v/(R*(celsius+273.15)*1000)
	
        ghk=2*F/1000*(co - ci*exp(a))*func(a)
}


FUNCTION func(a) {
	if (fabs(a) < 1e-4) {
		func = -1 + a/2
	}else{
		func = a/(1-exp(a))
	}
}

FUNCTION alpm(v(mV)) {
	:TABLE FROM -150 TO 150 WITH 200
	alpm = 0.1967*(-1.0*(v-15)+19.88)/(exp((-1.0*(v-15)+19.88)/10.0)-1.0)
}

FUNCTION betm(v(mV)) {
	:TABLE FROM -150 TO 150 WITH 200
	betm = 0.046*exp(-(v-15)/20.73)
}




DERIVATIVE states {     : exact when v held constant; integrates over dt step
        rates(v)
        m' = (minf - m)/taum
}

PROCEDURE rates(v (mV)) { :callable from hoc
        LOCAL a, qm
	
        TABLE taum, minf FROM -150 TO 150 WITH 3000 :Mitti
        
        qm = q10m^((celsius - 22)/10)
        a = alpm(v)
        taum = 1/((a + betm(v))*qm)
	

        minf = 1/(1+exp(-(v+11)/5.7)) ^0.5 
}


UNITSON