# Modified Morris-Lecar model from Prescott (2008, 2008) + T-current from Rubin (2004)+h-current from Izhikevich # modified from ml_salka.ode #stim used in experiments, mean=0, std=0.1 table Iext stim.tab #Iext(t)=0 nd=normal(0,0.4) par dc_noise=17.0057 aux noise=dc_noise+nd dV/dt = (i_dc(t)+amp*Iext(t)+dc_noise+nd-gna*minf(V)*(V-Vna)-gk*y*(V-VK)-gl*(V-Vl)-itf(V,mtinf(V),h)-gh*hh*(v-Vh))/c dy/dt = phi_y*(yinf(V)-y)/tauy(V) dh/dt = qht*(htinf(V)-h)/tauht(V) dhh/dt=(hhinf(V)-hh)/tauhh(V) par c=2 # HERE IS EVERYTHING YOU NEED TO KNOW ABOUT THE STIMULuS i_dc(t)=idc # idc is -20.89 voor -80, -2 voor -70, 16.27 voor -60, 31.43 voor -50 par idc=31 par amp=200 aux stim=i_dc(t)+amp*Iext(t) init V=-50, y=0, h=0, hh=0.03 # FAST INWARD CURRENT (INa or activation variable) # This is assumed to activate instantaneously with changes in voltage # voltage-dependent activation curve is described by m minf(V)=.5*(1+tanh((V-beta_m)/gamma_m)) # maximal conductance and reversal potential par beta_m=-1.2,gamma_m=18 par gna=20,vna=50 # DELAYED RECTIFIER CURRENT (IKdr or recovery variable) # this current activates more slowly than INa # In this code, activation of IKdr is controlled by y yinf(V)=.5*(1+tanh((V-beta_y)/gamma_y)) tauy(V)=1/cosh((V-beta_y)/(2*gamma_y)) # in the 2D model, varying beta_w shifts the w activation curve (w=y here) and can convert the neuron between class 1, 2, and 3 par beta_y=0, gamma_y=10 # maximal conductance and reversal potential par gk=20, vk=-100, phi_y=0.15 # LEAK CURRENT (Il) # just a passive leak conductance par gl=2, vl=-70 # T CURRENT (IT) itf(v,mt,ht)=gtbar*mt^2*ht*v # fast (instantaneous) activation mtinf(v) = 1/(1+exp(-(v+60)/6.2)) # slow inactivation htinf(v) = 1/(1+exp((v+84)/4)) tauht(v)=(28+apt*exp((v+25)/(-10.5))) par gtbar=20,qht=2.5,apt=1 # h CURRENT (Ih) hhinf(v)=1/(1+exp((Vhhalf-v)/k)) tauhh(v)=Cbase+Camp*exp(-(Vm-v)^2/sh^2) par Cbase=10, Camp=50, sh=20, Vhhalf=-82, k=-9, Vm=-75, Vh=-30, gh=1.5 # following parameters control duration of simulation and axes of default plot @ total=303000,xlo=0,xhi=6000,ylo=-100,yhi=50 @ meth=euler, dt=0.1, bounds=1000 @ MAXSTOR=3030010 done