: this model is builtin to neuron with suffix epsp
COMMENT
modified from syn2.mod
injected current with exponential rise and decay current defined by
i = 0 for t < onset and
i=amp*((1exp((tonset)/tau0))(1exp((tonset)/tau1)))
for t > onset
compare to experimental current injection:
i =  amp*(1exp(t/t1))*(exp(t/t2))
> tau1==t2 tau0 ^1 = t1^1 + t2^1
ENDCOMMENT
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}
NEURON {
POINT_PROCESS epsp
RANGE onset, tau0, tau1, imax, i, myv
NONSPECIFIC_CURRENT i
}
UNITS {
(nA) = (nanoamp)
(mV) = (millivolt)
(umho) = (micromho)
}
PARAMETER {
onset=0 (ms)
tau0=0.2 (ms)
tau1=3.0 (ms)
imax=0 (nA)
v (mV)
}
ASSIGNED { i (nA) myv (mV)}
LOCAL a[2]
LOCAL tpeak
LOCAL adjust
LOCAL amp
BREAKPOINT {
myv = v
i = curr(t)
}
FUNCTION myexp(x) {
if (x < 100) {
myexp = 0
}else{
myexp = exp(x)
}
}
FUNCTION curr(x) {
tpeak=tau0*tau1*log(tau0/tau1)/(tau0tau1)
adjust=1/((1myexp(tpeak/tau0))(1myexp(tpeak/tau1)))
amp=adjust*imax
if (x < onset) {
curr = 0
}else{
a[0]=1myexp((xonset)/tau0)
a[1]=1myexp((xonset)/tau1)
curr = amp*(a[0]a[1])
}
}
