#S Coombes Jan 2007
#A square-wave burster
#based on the addition of a Kca current to the Morris-Lecar model
#see http://www.math.pitt.edu/~bard/bardware/meth3/node9.html

param vk=-84,vl=-60,vca=120
param J=45,gk=8,gl=2,c=20
param v1=-1.2,v2=18
param v3=12,v4=17.4,phi=.23,gca=4
param mu=.2,ca0=10,eps=0.005,gkca=.25

v(0)=-18.7
w(0)=.071
ca(0)=10.39


Ica=gca*minf(V)*(V-Vca)
z=Ca/(Ca+Ca0)

dv/dt = ( J - ICa-(gk*w+gkca*z)*(V-VK)-gl*(V-Vl))/c
dw/dt = phi*(winf(V)-w)/tauw(V)
dca/dt=eps*(-mu*Ica-ca)


minf(v)=.5*(1+tanh((v-v1)/v2))
winf(v)=.5*(1+tanh((v-v3)/v4))
tauw(v)=1/cosh((v-v3)/(2*v4))


aux zbar=z
aux icaa=ica

@ xp=zbar,yp=v,xlo=0,xhi=1,ylo=-75,yhi=20,total=2000,dt=1,meth=gear,toler=1e-5
@ dtmax=5,dtmin=1e-10,bound=1000
done