TITLE CaL : L-type Ca current for Retinal Ganglion Cell from Benison et al (2001) : M.Migliore Nov. 2001 NEURON { SUFFIX calrgc USEION ca READ eca WRITE ica RANGE gbar GLOBAL minf, mtau } PARAMETER { gbar = 0.010 (mho/cm2) eca (mV) : must be explicitly def. in hoc v (mV) } UNITS { (mA) = (milliamp) (mV) = (millivolt) (pS) = (picosiemens) (um) = (micron) } ASSIGNED { ica (mA/cm2) minf mtau (ms) } STATE { m } BREAKPOINT { SOLVE states METHOD cnexp ica = gbar*m*m*(v - eca) } INITIAL { trates(v) m=minf } DERIVATIVE states { trates(v) m' = (minf-m)/mtau } PROCEDURE trates(vm) { LOCAL a, b a = trap0(vm,3,0.061,12.5) b = 0.058*exp(-(vm-10)/15) minf = a/(a+b) mtau = 1/(a+b) } FUNCTION trap0(v,th,a,q) { if (fabs(v-th) > 1e-6) { trap0 = a * (v - th) / (1 - exp(-(v - th)/q)) } else { trap0 = a * q } }