% Hodgkin-Huxley for Squid Giant Axon
% Except: v polarity reversed and rest potential shifted to -65
% And: m -> minf(v); n -> 0.85 - h

init v=-65.0, h=0.9

p iapp=0, cm=1, gnabar=120, gkbar=36, gl=0.3, vna=50, vk=-77, vl=-54

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))

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))

% variables

v' =  -(gnabar*minf(v)^3*h*(v-vna) + gkbar*(0.85-h)^4*(v-vk) + gl*(v-vl) - iapp)/cm
h' =  (hinf(v) - h)/tauh(v)

d