Extreme events in small ensemble of bursting neurons with chemical and electrical couplings.

We study the influence of additional electrical couplings on extreme events and chaotic dynamics observed in the minimal ensemble of two bursting Hindmarsh-Rose neurons with mutual chemical synaptic couplings. We discuss the relation between hyperchaos and extreme events in the system under study. Bifurcation scenarios of the emergence and destruction of complex dynamics contain extreme events were studied in detail. The main focus of the paper is on the transition to hyperchaos via codimension-two bifurcation. We hope that our study can help to gain more insights into the role of different types of couplings on the appearance and destruction of extreme events in neural networks.