TITLE Motoneuron L-type Calcium channels : : The parameters for this current come from V. Booth et al. J Neurophysiol 78:3371-3385, 1997 : Iterative equations : Modified by RP to provide calcium to a separate pool (caL)and to have adjustable equilibrium : potential vca NEURON { SUFFIX L_Ca_inact USEION caL READ ecaL WRITE icaL VALENCE 2 RANGE gcabar,icaL,m_inf,m,h GLOBAL vca,theta_m,kappa_m,theta_h,kappa_h } UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { gcabar = 0.0003 (mho/cm2) ecaL (mV) : eca can't be set here, only in hoc : celcius = 36 (degC) dt (ms) tau_m = 20 (ms) v (mV) vca=80 (mV) theta_m = -30 (mV) kappa_m = -6 (-mV) tau_h = 1500 (ms) theta_h = 14 (mV) kappa_h = 4 (-mV) } STATE { m h } ASSIGNED { icaL (mA/cm2) m_inf h_inf tadj } BREAKPOINT { SOLVE states METHOD cnexp icaL = gcabar * m *h* (v - vca) :I have tried this as m*m also } DERIVATIVE states { evaluate_fct(v) m' = (m_inf - m) / tau_m h' = (h_inf - h) / tau_h } UNITSOFF INITIAL { : : Q10 was assumed to be 3 for both currents : : tadj = 3.0 ^ ((celsius-36)/ 10 ) evaluate_fct(v) m = m_inf h = h_inf } PROCEDURE evaluate_fct(v(mV)) { m_inf = 1 / (1 + (Exp((v - theta_m)/ kappa_m))): / tadj h_inf = 1 / (1 + (Exp((v - theta_h)/ kappa_h))): / tadj } FUNCTION vtrap(x,y) { if (fabs(x/y) < 1e-6) { vtrap = y*(1 - x/y/2) }else{ vtrap = x/(Exp(x/y)-1) } } FUNCTION Exp(x) { if (x < -100) { Exp = 0 }else{ Exp = exp(x) } }