# model neuron of Shriki, Hansel, Sompolinsky
# Hodgkin-Huxley currents and A current
v[0..3]' = (-GL*(v[j]-VL)-GNA*MINF(v[j])^3*h[j]*(v[j]-VNA)-GK*n[j]^4*(v[j]-VK)-GA*AINF(v[j])^3*b[j]*(v[j]-VK)-GE[j]*(v[j]-VE)-GI[j]*(v[j]-VI)+I[j])/CM
h[0..3]' = PHIH*(ALPHAH(v[j])*(1-h[j])-BETAH(v[j])*h[j])
n[0..3]' = PHIN*(ALPHAN(v[j])*(1-n[j])-BETAN(v[j])*n[j])
b[0..3]' = (BINF(v[j])-b[j])/TAUB
s[0..3]' = (ALPHAS*SINF(v[j])*(1-s[j])-s[j])/TAUS
I[0..3]' = 0
# with hidden variables
GE0=0.03537+1.881*s0+s2
GE[1..3]=0
GI0=4*s3
GI[1..3]=0
# where
ALPHAM(v)=(v+35-SIGMAM)/10/(1-exp(-(v+35-SIGMAM)/10))
BETAM(v)=4*exp(-(v+60-SIGMAM)/18)
MINF(v) = 1/(1+BETAM(v)/ALPHAM(v))
ALPHAH(v)=0.07*exp(-(v+60-SIGMAH)/20)
BETAH(v)=1/(exp(-(v+30-SIGMAH)/10)+1)
ALPHAN(v)=0.01*(v+50-SIGMAN)/(1-exp(-(v+50-SIGMAN)/10))
BETAN(v)=0.125*exp(-(v+60-SIGMAN)/80)
AINF(v)=1/(exp(-(v+50)/20)+1)
BINF(v)=1/(exp((v+80)/6)+1)
SINF(v)=1/(1+exp(-(v-THETAS)/SIGMAS))
#
param CM=1  GL=0.2  VL=-65 
param GNA=100  VNA=55  PHIH=10  PHIN=10  SIGMAM=5  SIGMAH=16  SIGMAN=16 
param GK=40  VK=-80 
param GA=20  TAUB=20 
param VE=0  VI=-70
param ALPHAS=1 TAUS=100 
param THETAS=-20 SIGMAS=2

# for GL=0.2
init v[0..3]=-68.3737 h[0..3]=0.9820 n[0..3]=0.0631 b[0..3]=0.1259

#global 1 {v[j]} {sss[j]=ss[j]/tt[j]; ss[j]=0; ttt[j]=tt[j]; tt[j]=0}

global 1 t-500 {I2=3}
global -1 t-550 {I2=0}

@ MAXSTOR=1000000 TOTAL=1000 DT=0.01
done