: $Id: fvpre.mod,v 1.10 2003/07/29 23:37:22 billl Exp $ COMMENT synapse taken from Wang, X.-J. and Buzsaki G. (1996) Gamma oscillations by synaptic inhibition in a hippocampal interneuronal network. J. Neurosci. 16, 6402-6413. ENDCOMMENT NEURON { POINT_PROCESS gradNMDA RANGE gmax, g, i, alpha, beta, thetasyn,e, sigma GLOBAL mg NONSPECIFIC_CURRENT i POINTER vpre } UNITS { (nA) = (nanoamp) (mV) = (millivolt) (uS) = (microsiemens) } PARAMETER { gmax = 1e-3 (uS) alpha = 0.0163 (/ms) : 61.3 ms beta = 0.00292 (/ms) : 343 ms e = 0 (mV) : reserval potential thetasyn = 0 (mV) : spike threshold mg = 1 (mM) : external magnesium concentration sigma = 2 : !!! } ASSIGNED { vpre (mV) v (mV) i (nA) g (uS) B : magnesium block } STATE { s } INITIAL { s = alpha*F(vpre)/(alpha*F(vpre)+beta) } BREAKPOINT { SOLVE state METHOD cnexp B = mgblock(v) g = gmax*s*B i = g*(v - e) } DERIVATIVE state { s' = alpha*F(vpre)*(1-s) - beta*s } FUNCTION F (v1 (mV)) { F = 1/(1 + exp(-(v1-thetasyn)/sigma)) } FUNCTION mgblock(v(mV)) { TABLE DEPEND mg FROM -140 TO 80 WITH 1000 : from Jahr & Stevens mgblock = 1 / (1 + exp(0.062 (/mV) * -v) * (mg / 3.57 (mM))) }