TITLE h current for Octopus cells of Cochlear Nucleus : From Bal and Oertel (2000) : M.Migliore Oct. 2001 NEURON { SUFFIX hcno NONSPECIFIC_CURRENT i RANGE gbar GLOBAL hinf, tau1,tau2 } PARAMETER { gbar = 0.0005 (mho/cm2) vhalf1 = -50 (mV) : v 1/2 for forward vhalf2 = -84 (mV) : v 1/2 for backward gm1 = 0.3 (mV) : slope for forward gm2 = 0.6 (mV) : slope for backward zeta1 = 3 (/ms) zeta2 = 3 (/ms) a01 = 0.008 a02 = 0.0029 frac=0.0 thinf = -66 (mV) : inact inf slope qinf = 7 (mV) : inact inf slope q10=4.5 : from Magee (1998) eh (mV) : must be explicitly def. in hoc celsius v (mV) } UNITS { (mA) = (milliamp) (mV) = (millivolt) (pS) = (picosiemens) (um) = (micron) } ASSIGNED { i (mA/cm2) thegna (mho/cm2) hinf tau1 tau2 } STATE { h1 h2 } BREAKPOINT { SOLVE states METHOD derivimplicit thegna = gbar*(h1*frac + h2*(1-frac)) i = thegna * (v - eh) } INITIAL { trates(v) h1=hinf h2=hinf } DERIVATIVE states { trates(v) h1' = (hinf - h1)/tau1 h2' = (hinf - h2)/tau2 } PROCEDURE trates(v) { LOCAL qt qt=q10^((celsius-33)/10) tau1 = bet1(v)/(qt*a01*(1+alp1(v))) tau2 = bet2(v)/(qt*a02*(1+alp2(v))) hinf = 1/(1+exp((v-thinf)/qinf)) } FUNCTION alp1(v(mV)) { alp1 = exp(1.e-3*zeta1*(v-vhalf1)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION bet1(v(mV)) { bet1 = exp(1.e-3*zeta1*gm1*(v-vhalf1)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION alp2(v(mV)) { alp2 = exp(1.e-3*zeta2*(v-vhalf2)*9.648e4/(8.315*(273.16+celsius))) } FUNCTION bet2(v(mV)) { bet2 = exp(1.e-3*zeta2*gm2*(v-vhalf2)*9.648e4/(8.315*(273.16+celsius))) }