: $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, 64026413.
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 = 1e3 (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)*(1s)  beta*s
}
FUNCTION F (v1 (mV)) {
F = 1/(1 + exp((v1thetasyn)/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)))
}
