Figure 13

Two-fast/one-slow analysis for g _BK = 0.4 nS, C _m = 10 pF and different values of g _K . The black "z-curve" is the curve of equilibria of the V-n fast subsystem. This has stable (solid) and unstable (dashed) branches. (a) g _K = 0.1 nS, the full system with stable equilibrium (A₁) is in a depolarized steady state. (b) g _K = 4 nS, the fast subsystem has an unstable limit cycle that emerges from the subcritical Hopf bifurcation (subHB). Pseudo-plateau bursting (PPB, black trajectory) is produced. The equilibrium of the full system (A₃) is unstable. (c) g _K = 5.1 nS, the full system produces periodic spiking that appears unrelated to the fast subsystem bifurcation structure. The equilibrium point of the full system (A) is unstable. In all panels the system is bistable over a range of c-values. The points A₁ and A₃ are the same equilibrium points as A₁ and A₃ in Fig. 5, respectively.