Chimera states in chemically coupled neurons based on the Hindmarsh–Rose model

We investigate the emergence of chimera states in networks of chemically coupled Hindmarsh–Rose neurons. First, we analyze the dynamics of a single pair of bidirectionally coupled neurons to identify the parameter ranges and initial conditions leading to spike and burst synchronization. Using these findings, we construct a minimal network of three pairs of neurons, where two pairs exhibit fixed spike or burst firing patterns and perturb a central pair. By varying the synaptic coupling strengths, we observe the coexistence of regular spiking, irregular spiking, and bursting behaviors, resulting in chimera states. These results show that chimera states can be induced over extended regions of the coupling-strength parameter space in small chemical-synapse networks and provide new insights into the mechanisms underlying partial synchronization in neuronal systems.