COMMENT
Since this is an electrode current, positive values of i depolarize the cell
and in the presence of the extracellular mechanism there will be a change
in vext since i is not a transmembrane current but a current injected
directly to the inside of the cell.
ENDCOMMENT
NEURON {
POINT_PROCESS dbsStim
RANGE del, dur, amp, pw, period, actPrb, adLat, active, i
ELECTRODE_CURRENT i
}
UNITS {
(nA) = (nanoamp)
}
PARAMETER {
del = 0 (ms)
dur = 1e9 (ms) <0,1e9>
amp = 0 (nA)
pw = .1 (ms)
period = 500 (ms)
actPrb = 1
adLat = 2
active = 0
}
ASSIGNED {
i (nA)
offtime (ms)
}
INITIAL {
offtime = period - pw
i = 0
if (del <= 0) {
del = 0
}
if (active) {
net_send(del, 1) : initiate dbs sequence
net_send(del+dur, 4) : terminate dbs sequence
}
}
BREAKPOINT {
i = i
}
NET_RECEIVE (w) {LOCAL tmp
if (flag == 0 && w >= 0) {
: initiate dbs sequence from external event
active = 1
net_send(del, 1)
net_send(del+dur, 4)
} else {
if (flag == 1 && active) { : dbs pulse occured
tmp = scop_random()
if (tmp <= actPrb) {
:may eventually want to add separate checks based on probability of propagation
:in antidromic [net_send(adLat, 2)]
:and orthodromic [net_event(t)] directions
net_send(adLat, 2) : turn on current after delay
net_send(adLat+pw, 3) : turn off current
net_event(t) : signal orthodromic events to occur
}
net_send(adLat+offtime, 1) : come back for next pulse
} else {
if (flag == 2) {
i = amp : up state of antidromic pulse
} else {
if (flag == 3) {
i = 0 : down state of antidromic pulse
} else {
if (flag == 4) {
active = 0
}
}
}
}
}
}