TITLE NaP - persistent sodium current for nucleus accumbens COMMENT Magistretti J, Alonso A (1999). "Biophysical properties and slow voltage-dependent inactivation of a sustained sodium current in entorhinal cortex layer-II principal neurons." J Gen Phys, 114: 491-509. Traub RD, Buhl EH et al (2003). "Fast rhythmic bursting can be induced in layer 2/3 cortical neurons by enhancing persistent na+ conductance or by blocking BK channels." J Neurophys 89: 909-921. Jason Moyer 2004 - jtmoyer@seas.upenn.edu ENDCOMMENT UNITS { (mA) = (milliamp) (mV) = (millivolt) (S) = (siemens) } NEURON { SUFFIX nap USEION na READ ena WRITE ina RANGE gnabar, ina } PARAMETER { gnabar = 4e-5 (S/cm2) : 4e-5 in soma; 1.3802e-7 in dends mvhalf = -52.6 (mV) : Magistretti 1999, Fig 4 mslope = -4.6 (mV) : Magistretti 1999, Fig 4 hvhalf = -48.8 (mV) : Magistretti 1999, Fig 4 hslope = 10.0 (mV) : Magistretti 1999, Fig 4 qfact = 3 } STATE { m h } ASSIGNED { ena (mV) v (mV) ina (mA/cm2) gna (S/cm2) minf hinf mtau (ms) : Traub 2003, Table A2 } BREAKPOINT { SOLVE state METHOD cnexp gna = gnabar * m * h ina = gna * ( v - ena ) : VERBATIM : printf("Ena is %g\n", ena); : ENDVERBATIM } INITIAL { rates(v) m = minf h = hinf } FUNCTION_TABLE tauhnap (v(mV)) (ms) : Magistretti 1999, Fig 8A DERIVATIVE state { rates(v) m' = (minf - m) / mtau h' = (hinf - h) / (tauhnap(v)/qfact) } PROCEDURE rates(v (mV)) { TABLE minf, hinf, mtau FROM -200 TO 200 WITH 201 minf = 1 / (1 + exp( (v - mvhalf) / mslope)) hinf = 1 / (1 + exp( (v - hvhalf) / hslope)) UNITSOFF if (v < -40) { : Traub 2003, Table A2 mtau = 0.025 + 0.14 * exp( (v + 40 ) / 10) } else { mtau = 0.02 + 0.145 * exp( (-v - 40) / 10) } UNITSON }