R1 R2 Rm rho 6.6 -6 2.1 -6 1 -6 J_tau J_infinity J K_inh K_inh I rho Vm G_i Km G_i 4 -5 rho V1 G G_i K1 G_i 1 G K1 I Ki I rho V2 G Jm G_i K2 G_i 1 G K2 Vs Rm 4 rho 4 L 4 Rm 4 rho 4 Ks 4 rho 4 L 4