We study the formation and suppression of spiral wave patterns in a lattice of memristive FitzHugh–Nagumo neurons that are connected through chemical coupling.

While earlier works focused predominantly on diffusive coupling, we focus on various parameters that determine the properties of chemical synapses, in particular their firing threshold, the sigmoidal slope, and the reversal potential.

Based on physiologically plausible scenarios, we also aim to determine the most probable realistic values of these parameters that facilitate the formation of spiral waves.

Furthermore, we study the destabilizing impact of external direct and Faradaic currents on spiral wave patterns, showing that they commonly convert into other turbulent patterns or vanish altogether. Interestingly, however, during the destabilization process, counter-rotating spirals that then collide and generate complex patterns can also be observed.

D. N. Hajian, F. Parasteh, K. Rajagopal, S. Jafari, M. Perc, When do chemical synapses modulate the formation of spiral waves?, Nonlinear Dynamics (2023) DOI: 10.1007/s11071-023-08994-7.