TITLE hyperpolarization-activated current (H-current) COMMENT Based on Williams and Stuart J. Neurophysiol 83:3177,2000 ENDCOMMENT INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} NEURON { SUFFIX iH USEION h READ eh WRITE ih VALENCE 1 RANGE gbar, h_inf, tau, ih GLOBAL t0,t1,off, slo, offt1, offt2, slot1, slot2 GLOBAL q10, temp, tadj, vmin,vmax } UNITS { (mA) = (milliamp) (mV) = (millivolt) (molar) = (1/liter) (mM) = (millimolar) (pS) = (picosiemens) (um) = (micron) } PARAMETER { v (mV) celsius (degC) eh (mV) gbar = 0.0 (pS/um2) off = -91 (mV) : V1/2 of activation slo=6 (mV) : slope of activation t0 = 2542.5883549 (ms) : parameters for time constant of activation t1 = 11.40250855 (ms) offt1 = 0 (mV) offt2 = 0 (mV) slot1 = 40.1606426 (mV) slot2 = 16.1290323 (mV) temp = 21 (degC) : original temp q10 = 2.3 : temperature sensitivity vmin = -120 (mV) vmax = 100 (mV) } ASSIGNED { ih (mA/cm2) h_inf tau (ms) tadj } STATE { h } INITIAL { rates(v) h = h_inf } BREAKPOINT { SOLVE states METHOD cnexp ih = (1e-4) * gbar * h * (v-eh) } DERIVATIVE states { rates(v) h' = (h_inf-h)/tau } PROCEDURE rates( v (mV)) { tadj= q10^((celsius-22)/10) h_inf = 1/(1+exp((v-off)/slo)) tau = 1/(tadj*(exp(-(v-offt1)/slot1)/t0+exp((v-offt2)/slot2)/t1)) }