TITLE PUMP : FORREST MD (2014) Two Compartment Model of the Cerebellar Purkinje Neuron UNITS { (molar) = (1/liter) (pA) = (picoamp) (mV) = (millivolt) (uS) = (micromho) (mA) = (milliamp) (mM) = (millimolar) } INDEPENDENT {v FROM -100 TO 50 WITH 50 (mV)} NEURON { SUFFIX pump : USEION Na WRITE iNa VALENCE 1 : USEION na READ nai USEION na READ nai WRITE ina USEION k WRITE ik RANGE inapump,ipumpmax,n,km,kk,k,decline,initialdensity,lex,red } PARAMETER { dt (ms) nai (mM) : ipumpmax = 0.04 (mA/cm2) km = 10.0 (mM) n=1.5 kk = 10.0 (mM) k = 1.5 nainit = 4 (mM) celsius = 35 (degC) T = 1 decline = 0 initialdensity = 1 (mA/cm2) lex = 100000 (ms) : if 100 then we get fast declining pump. if like 100,000. then we dont really get decline red = 3000 (ms) } ASSIGNED { ina (mA/cm2) iNa (mA/cm2) ik (mA/cm2) inapump (mA/cm2) ipumpmax (mA/cm2) inapumping (mA/cm2) xm t_wait (ms) } INITIAL{ ipumpmax = initialdensity t_wait = 0 } BREAKPOINT {LOCAL fnk inapump = ipumpmax if (decline == 1) { if ( t > red) { if (t_wait < lex) {t_wait = t_wait + dt } else { ipumpmax = ipumpmax - 0.001 t_wait = 0 : this resets the counter. } } if (ipumpmax < 0) {ipumpmax = 0} } : fnk = (v + 70)/(v+70.1) : fnk = (v + 65)/(v+65.1) : fnk = 1 : fnk = (v + 70)/(v + 80) fnk = (v + 75)/(v + 80) inapump = ((ipumpmax*fnk)/(1+exp((km-nai)/n))) ina = 3.0*inapump ik = -2.0*inapump } COMMENT INITIAL{ nai = nainit} ENDCOMMENT