% Classical Hodgkin-Huxley parameters for Squid Giant Axon
% Except: v polarity reversed and rest potential shifted to -65
% (cf. Hansel, Mato, and Meunier, Europhys. Lett. 23:367-372, 1993)

init v=-65.0, h=0.9, n=0.1, m=0.1

p iapp=0, cm=1, gnabar=120, gkbar=36, gl=0.3, vna=50, vk=-77, vl=-54.4

alpham(v) = 0.1*(v+40)/( 1 - exp(-(v+40)/10) )
betam(v) =  4*exp(-(v+65)/18)
minf(v) = 1/(1+betam(v)/alpham(v))
taum(v) = 1/(alpham(v) + betam(v))

alphah(v) =  0.07*exp(-(v+65)/20)
betah(v) = 1/( 1 + exp(-(v+35)/10) )
hinf(v) = 1/(1+betah(v)/alphah(v))
tauh(v) = 1/(alphah(v) + betah(v))

alphan(v) = 0.01*(v + 55)/(1 - exp(-(V + 55)/10))
betan(v) = 0.125*exp(-(V + 65)/80)
ninf(v) = 1/(1+betan(v)/alphan(v))
taun(v) = 1/(alphan(v) + betan(v))

% variables

v' =  -(gnabar*m^3*h*(v-vna) + gkbar*n^4*(v-vk) + gl*(v-vl) - iapp)/cm
h' =  (hinf(v) - h)/tauh(v)
n' =  (ninf(v) - n)/taun(v)
m' =  (minf(v) - m)/taum(v)

d