TITLE K-DR
: K-DR current for Mitral Cells from Wang et al (1996)
: M.Migliore Jan. 2002

NEURON {
	SUFFIX kdrmt
	USEION k READ ek WRITE ik
	RANGE  gbar
	GLOBAL minf, mtau
}

PARAMETER {
	gbar = 0.002   	(mho/cm2)	
								
	celsius
	ek		(mV)            : must be explicitly def. in hoc
	v 		(mV)
	a0m=0.0035
	vhalfm=-50
	zetam=0.055
	gmm=0.5

	q10=3
}


UNITS {
	(mA) = (milliamp)
	(mV) = (millivolt)
	(pS) = (picosiemens)
	(um) = (micron)
} 

ASSIGNED {
	ik 		(mA/cm2)
	minf 		mtau (ms)	 	
}
 

STATE { m}

BREAKPOINT {
        SOLVE states METHOD cnexp
	ik = gbar*m*(v - ek)
} 

INITIAL {
	trates(v)
	m=minf  
}

DERIVATIVE states {   
        trates(v)      
        m' = (minf-m)/mtau
}

PROCEDURE trates(v) {  
	LOCAL qt
        qt=q10^((celsius-24)/10)
        minf = 1/(1 + exp(-(v-21)/10))
	mtau = betm(v)/(qt*a0m*(1+alpm(v)))
}

FUNCTION alpm(v(mV)) {
  alpm = exp(zetam*(v-vhalfm)) 
}

FUNCTION betm(v(mV)) {
  betm = exp(zetam*gmm*(v-vhalfm)) 
}