TITLE transient potassium (A-) current COMMENT Equations from Huguenard JR, McCormick DA (1992) Simulation of the currents involved in rhythmic oscillations in thalamic relay neurons. J Neurophys 68(4): 1373-1383. >< Temperature adjusts time constants measured at 23.5 degC. >< Written by Arthur Houweling for MyFirstNEURON. ENDCOMMENT NEURON { SUFFIX iA USEION k READ ek WRITE ik RANGE gk, minf, mtau, hinf, htau, ik } UNITS { (mA) = (milliamp) (mV) = (millivolt) } PARAMETER { v (mV) celsius (degC) ek (mV) gk= 3.45e-3 (mho/cm2) } STATE { m h } ASSIGNED { ik (mA/cm2) mtau (ms) htau (ms) minf hinf tadj } BREAKPOINT { SOLVE states METHOD cnexp ik= gk* m^4* h* (v- ek) } DERIVATIVE states { rates() m'= (minf- m)/ mtau h'= (hinf- h)/ htau } INITIAL { UNITSOFF tadj= 3^ ((celsius- 23.5)/ 10) rates() m= minf h= hinf } PROCEDURE rates() { minf= 1/ (1+exp(-(v+60)/8.5)) hinf= 1/ (1+ exp((v+ 78)/ 6)) mtau= (1/ (exp((v+ 35.82)/ 19.69)+ exp(-(v+ 79.69)/ 12.7))+ 0.37)/ tadj if (v< -63) { htau= 1/ (( exp((v+ 46.05)/ 5)+ exp(-(v+ 238.4)/ 37.45)))/ tadj } else { htau= 19/ tadj } }