Fig. 10

(A) Magnification of the interspike bifurcation-diagram (IBD) for $I=3.5$ in the bistable region CR2 from Figure 8. It reveals two coexisting bursting orbits (shown in red and blue) at $x_0=-0.9909$ in the phase space of the model: the split between the solutions takes place near the saddle after the orbits departs in the direction determined by the unstable separatrices. (B) Two coexisting orbits corresponding to single and duplet spiking.