TITLE 3D diffusion
NEURON{
POINT_PROCESS diff_5HT
RANGE serotonin,h,c0cleft
RANGE Deff,tx1, diff, a}
UNITS{
(molar)=(1/liter)
(uM)=(micromolar)
(um)=(micron)
(nA)=(nanoamp)
}
CONSTANT {
PI=3.1415927
}
PARAMETER {
Deff= 0.000465 (um2/ms):effective diffusion coefficient
c0cleft = 2 (uM):initial quantity atp
h(um)
tx1(ms)
k = 0.00055
vmax = 0.0175
km = 0.005
a = 20 :coefficient of reuptake
}
ASSIGNED{
serotonin (uM)
diff (uM)
}
INITIAL {
:tx1=10
serotonin = 0
diff = 0
}
BREAKPOINT
{
at_time(tx1)
if (t<=tx1){
serotonin = 0
diff = 0
}
if(t>tx1) {
UNITSOFF
diff = (2*c0cleft*exp(h/(4*Deff*(tx1-t))))/sqrt(4*4*4*PI*PI*PI*Deff*Deff*Deff*(t-tx1)*(t-tx1)*(t-tx1))
serotonin = diff - a*((vmax*diff)/(km + diff))
if(serotonin > c0cleft){serotonin=c0cleft}
if(serotonin < 0){serotonin=0}
}
}
NET_RECEIVE (weight)
{
tx1=t
}