TITLE Kd current COMMENT Equations from Lyle J Borg-Graham Interpretation of Data and Mechanisms for Hippocampal Pyramidal Cell Models A Chapter in "Cerebral Cortex, Volumne 13: Cortical Models" Edited by P.S.Ulinski, E.G.Jones and A.Peters,New York:plenum Press,1998 The Krasnow Institute George Mason University Copyright Maciej Lazarewicz, 2001 (mlazarew@gmu.edu) All rights reserved. ENDCOMMENT NEURON { SUFFIX kdBG USEION k WRITE ik RANGE gbar,ik GLOBAL xtau, ytau, xinf, yinf } UNITS { (S) = (siemens) (mA) = (milliamp) (mV) = (millivolt) FARADAY = (faraday) (coulombs) R = (k-mole) (joule/degC) } PARAMETER { gbar = 1.0e-3 (S/cm2) Ky = 2.0e-4 (1/ms) gammay = 0.0 (1) zettax = 3.0 (1) zettay = -2.5 (1) vhalfx = -63.0 (mV) vhalfy = -73.0 (mV) taox = 1.0 (ms) taoy = 0.0 (ms) } ASSIGNED { v (mV) ik (mA/cm2) celsius (degC) xtau (ms) ytau (ms) xinf (1) yinf (1) q10 (1) T (K) } STATE { xs ys } BREAKPOINT { SOLVE states METHOD cnexp ik= gbar * xs^4 * ys^4 * ( v + 95.0 ) } DERIVATIVE states { rates() xs'= (xinf- xs)/ xtau ys'= (yinf- ys)/ ytau } INITIAL { T = celsius + 273.15 q10= 1.0^( (celsius-35.0) / 10.0(K) ) rates() xs= xinf ys= yinf } PROCEDURE rates() { LOCAL a, b a = q10*exp( (1.0e-3)* zettax*(v-vhalfx)*FARADAY/(R*T) ) b = q10*exp( (1.0e-3)* -zettax*(v-vhalfx)*FARADAY/(R*T) ) xinf = a / ( a + b ) xtau = taox a = q10*Ky*exp( (1.0e-3)* zettay* gammay *(v-vhalfy)*FARADAY/(R*T) ) b = q10*Ky*exp( (1.0e-3)* -zettay*(1.0-gammay)*(v-vhalfy)*FARADAY/(R*T) ) yinf = a / ( a + b ) ytau = 1.0 / ( a + b ) + taoy }