Code: Select all

```
NEURON {
POINT_PROCESS ExpSynSTDP
RANGE tau, e, i, d, p, dtau, ptau, verbose, learning, LR, maxWeight, minWeight
NONSPECIFIC_CURRENT i
}
UNITS {
(nA) = (nanoamp)
(mV) = (millivolt)
(uS) = (microsiemens)
}
PARAMETER {
tau = 0.1 (ms) <1e-9,1e9>
e = 0 (mV)
d = 0 <0,1>: depression factor (multiplicative to prevent < 0)
p = 0 : potentiation factor (additive, non-saturating)
dtau = 34 (ms) : 34 depression effectiveness time constant
ptau = 17 (ms) : 17 Bi & Poo (1998, 2001)
verbose = 0
learning = 1
LR = 0.0001
maxWeight = 1
minWeight = 0
}
ASSIGNED {
v (mV)
i (nA)
tpost (ms)
}
STATE {
g (uS)
}
INITIAL {
g=0
tpost = -1e9
net_send(0, 1)
}
BREAKPOINT {
SOLVE state METHOD cnexp
i = g*(v - e)
}
DERIVATIVE state {
g' = -g/tau
}
NET_RECEIVE(w (uS), tpre (ms)) {
INITIAL { tpre = -1e9 }
if (flag == 0) { : presynaptic spike (after last post so depress)
g = g + w
if(learning) {
if (w>=minWeight){
w = w-LR*d*exp((tpost - t)/dtau)
if(w<=minWeight){
w=minWeight
}
:w = w*LR*d*(1-(exp((tpost - t)/dtau)))
if(verbose) {
printf("dep: w=%g \t dw=%g \t dt=%g\n", w, -LR*d*exp((tpost - t)/dtau), tpost-t)
}
}
}
tpre = t
}else if (flag == 2) { : postsynaptic spike
tpost = t
FOR_NETCONS(w1, tp) { : also can hide NET_RECEIVE args
if(learning) {
if (w1<=maxWeight){
w1 = w1+LR*p*exp((tp - t)/ptau)
if (w1>maxWeight){
w1 = maxWeight
}
if(verbose) {
printf("pot: w=%g \t dw=%g \t dt=%g\n", w1, (LR*p*exp((tp - t)/ptau)), t - tp)
}
}
}
}
} else { : flag == 1 from INITIAL block
WATCH (v > -20) 2
}
}
```

My first question: is there anywhere I can find documentation for the WATCH command? Neither https://www.neuron.yale.edu/neuron/stat ... ight=nmodl nor https://www.neuron.yale.edu/neuron/stat ... modl2.html appear to say anything about it.

Second, how do we know flag==0 implies a pre-synaptic spike? (line 54) Is setting flag=0 the default behavior of NEURON/NMODL when a pre-synaptic spike occurs? I could not find this anywhere in the documentation, either. Thank you.