Bursting in cerebellar stellate cells induced by pharmacological agents: Non-sequential spike adding
Fig 7
The effects of gK(Ca) on the dynamics of the full system (1).
Bifurcation diagram of the full system (1) with respect to gK(Ca) using the L2-norm of the state variables. Two subcritical Hopf bifurcations HB1 and HB2 are present along the branch of equilibria (black). The equilibria are unstable (dotted) between HB1 and HB2 and stable otherwise (solid). The envelope of periodic orbits emanating from HB1 (olive) is unstable and terminates at a homoclinic bifurcation, denoted by HC. The family of periodic orbits emanating from HB2 is unstable. After a drastic change in the L2-norm of the state variables, the envelope becomes stable at a period-doubling bifurcation (PD). This envelope becomes unstable at a saddle-node bifurcation of periodic orbits (SNP1) before undergoing the spike-adding process, and then becomes stable again at another saddle-node bifurcation of periodic orbits (SNP2). The two instances of drastic changes in the L2-norm of the state variables inside the right black box are further magnified in the inset. The set of (colored) curves inside the left gray box shows isolas of square-wave BPOs with different number of spikes. These isolas are further magnified in Fig 8A.