bertram2000_BJ_00.ode

# Phantom bursting model, with 2 fast and 2 slow variables. # Bertram et al, Biophys. J. 79:2880-2892, 2001. # For Fig. 2, set gs1=20. # For Fig. 3, set gs1=7, set v(0)=0.6, set total integration time = 120000. # For Fig. 4, set gs1=3, set v(0)=0.6, set total integration time = 300000.

# Units: V = mV; t = ms; g = pS; I = fA

# Initial conditions v(0)=-43.0 n(0)=0.03 s1(0)=0.1 s2(0)=0.434

# Parameters

param lambda=1.1, gca=280, gk=1300 param gl=25, vs1=-40, taus1=1000, vs2=-42, taus2=120000, gs2=32 param gs1=20, vl=-40

param vca=100, vk=-80, cm=4524 param tnbar=9.09, vm=-22, vn=-9, sm=7.5, sn=10

param ss1=0.5, ss2=0.4

# activation and time-constant functions minf(v) = 1.0/(1.0+exp((vm-v)/sm)) ninf(v) = 1.0/(1.0+exp((vn-v)/sn)) taun(v) = tnbar/(1.0+exp((v-vn)/sn)) s1inf(v) = 1.0/(1.0+exp((vs1-v)/ss1)) s2inf(v) = 1.0/(1.0+exp((vs2-v)/ss2))

# ionic currents ica(v) = gca*minf(v)*(v-vca) ik(v) = gk*n*(v-vk) il(v) = gl*(v-vl) is1(v) = gs1*s1*(v-vk) is2(v) = gs2*s2*(v-vk)

# differential equations v' = -( ica(v) + ik(v) + il(v) + is1(v) + is2(v) )/cm n' = lambda*(ninf(v) - n)/taun(v) s1' = (s1inf(v) - s1)/taus1 s2' = (s2inf(v) - s2)/taus2

# XPP parameters @ meth=cvode, dtmax=1, dt=5, total=30000, maxstor=100000 @ bounds=100000000, xp=t, yp=v, toler=1.0e-6, atoler=1.0e-6 @ xlo=0, xhi=30000, ylo=-70, yhi=-10

done