#  T-current model
init v=-94,ht=.95
par I=0,c=.29
par ip=0,t_on=50,t_off=150
v'=(I -ileak-it+istep(t))/c
istep(t)=ip*heav(t-t_on)*heav(t_off-t)
# the current is a step function with amplitude ip
# passive leaks
par ena=45,ek=-105,eca=145
par gkleak=.007,gnaleak=.0005
Ileak=gkleak*(v-ek)+gnaleak*(v-ena)
#
aux i_leak=ileak
#
# IT and calcium dynamics -- transient low threshold
# permeabilites in 10-6 cm^3/sec
#
par gt=2
mt=1/(1+exp(-(v+52)/7.4))
IT=gt*ht*mt^2*(v-eca)
htinf=1/(1+exp((v+80)/5))
tauht=22.7+.27/(exp((v+48)/4)+exp(-(v+407)/50))
ht'=(htinf-ht)/tauht
@ dt=.25,total=500,xp=v,yp=ht,xlo=-100,xhi=40,ylo=-.1,yhi=1
@ nmesh=100,bounds=1000
done