Qualitative methods for case study of the Hindmarch–Rose model

We demonstrate that bifurcations of periodic orbits underlie the dynamics of the Hindmarsh–Rose model and other square-wave bursting models of neurons of the Hodgkin–Huxley type. Such global bifurcations explain in-depth the transitions between the tonic spiking and bursting oscillations in a model. We show that a modified Hindmarsh–Rose model can exhibit the blue sky bifurcation, and a bistability of the coexisting tonic spiking and bursting activities.