# from Rho and Prescott, PLoS Comput Biol 2012 # to be run in XPP # code for 3-D "ungrouped" model; see Fig 7 from paper # DIFFERENTIAL EQUATIONS dv/dt = (Istim-gna*minf(V)*(V-Vna)-gk*w*(V-VK)-gl*(V-Vl)-gsubNa*yNa*(V-Vna)-gsubK*yK*(V-Vk))/cap dw/dt = phi_w*(winf(V)-w)/tauw(V) dyNa/dt = phi_yna*(yna_inf(V)-yNa)/tauyna(V) dyK/dt = phi_yk*(yk_inf(V)-yK)/tauyk(V) # FUNCTIONS AND PARAMETERS minf(v)=.5*(1+tanh((v-beta_m)/gamma_m)) winf(v)=.5*(1+tanh((v-beta_w)/gamma_w)) yna_inf(v)=.5*(1+tanh((v-beta_y)/gamma_y)) yk_inf(v)=.5*(1+tanh((v-beta_y)/gamma_y)) tauw(v)=1/cosh((v-beta_w)/(2*gamma_w)) tauyna(v)=1/cosh((v-beta_y)/(2*gamma_y)) tauyk(v)=1/cosh((v-beta_y)/(2*gamma_y)) param Istim=0 param vna=50,vk=-100,vl=-70 param gk=20,gl=2,gna=20 param beta_m=-1.2,gamma_m=18 param beta_w=-13,gamma_w=10 # for some simulations, beta_w was -21 param phi_w=.15 # This code is designed to implement either a subthreshold Na or K current by setting the corresponding gsub to >0 # Leave the other gsub at 0 param gsubNa=0,gsubK=0 param beta_y=-23,gamma_y=9, param phi_yna=0.3,phi_yk=0.15 param cap=2 # INITIAL CONDITIONS yNa(0)=0 yK(0)=0 V(0)=-70 w(0)=0.000025 # ALWAYS USE EULER! - Actually this is only true for noise @ total=10000,dt=.05,xlo=-100,xhi=60,ylo=-.125,yhi=.6,xp=v,yp=w @ meth=euler @ MAXSTOR=1000000,bounds=10000 done