# Modified Morris-Lecar model from Prescott (2008, 2008) # modified from ml_salka.ode #stim used in experiments, mean=0, std=0.1 table Iext stim.tab #Iext(t)=0 nd=normal(0,0.3) par dc_noise=2.2218 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))/c # dy/dt = phi_y*(yinf(V)-y)/tauy(V) dy/dt = if(y<0)then(0.1)else(if(y>1)then(-0.1)else(phi_y*(yinf(V)-y)/tauy(V))) par c=2 i_dc(t)=idc # idc is -20.42 voor -80, -1.15 voor -70, 16.8 voor -60, 31.25 voor -50 par idc=32 init V=-50, y=0 par amp=150 aux stim=i_dc(t)+amp*Iext(t) # 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 # 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