TITLE Ca-dependent potassium current (C-current) COMMENT ********************************************* reference: Yamada, Koch & Adams (1989) Meth. in Neuronal Modeling, MIT press found in: bullfrog sympathetic ganglion cells ********************************************* Assembled for MyFirstNEURON by Arthur Houweling ENDCOMMENT INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} NEURON { SUFFIX iC USEION k READ ek WRITE ik USEION ca READ cai RANGE gkbar, m_inf, tau_m, ik } UNITS { (mA) = (milliamp) (mV) = (millivolt) (mM) = (milli/liter) } PARAMETER { v (mV) celsius (degC) dt (ms) ek (mV) cai (mM) gkbar= 0.00345 (mho/cm2) } STATE { m } ASSIGNED { ik (mA/cm2) tau_m (ms) m_inf tadj } BREAKPOINT { SOLVE states :METHOD euler ik = gkbar * m * (v - ek) } :DERIVATIVE states { : rates(v,cai) : : m'= (m_inf-m) / tau_m :} PROCEDURE states() { rates(v,cai) m= m + (1-exp(-dt/tau_m))*(m_inf-m) } UNITSOFF INITIAL { tadj = 3^((celsius-23.5)/10) rates(v,cai) m = m_inf } PROCEDURE rates( v(mV), cai(mM)) { LOCAL a,b a = 250 * cai * exp(v/24) b = 0.1 * exp(-v/24) tau_m = 1/(a+b) / tadj m_inf = a/(a+b) } UNITSON