# stoch_ml.ode
# initial data
v(0)=-40
w(0)=1
# wiener process
wiener b
#  parameter N for number of channels
par n=100
# functions for the gates
minf=.5*(1+tanh((v-v1)/v2))
winf=.5*(1+tanh((v-v3)/v4))+.05
tau=1/(phi*cosh((v-v3)/(2*v4)))
# variance for the potassium channel gate, w
gam=((1-2*winf)*w+winf)/(n*tau)
# differential equations
dv/dt=(iapp-gl*(v-vl)-gk*max(w,0)*(V-Vk)-gca*minf*(v-vca))/c
dw/dt=(winf-w)/tau+sqrt(gam)*b
# parameters
par iapp=10,vk=-70,c=1,gk=2,vca=100,gca=1.333,vl=-50,gl=.5,v1=-1,v2=15
par phi=.333,v3=10,v4=14.5
# integration control
@ total=500,dt=.01,nout=10,meth=euler
# plot control - shows voltage vs time
@ xlo=0,xhi=500,ylo=-60,yhi=50,maxstor=10000
done