Effects of multiplicative-noise and coupling on synchronization in thermosensitive neural circuits

Functional neural circuits had been proposed by taking physical effects into considerations. Both the synapse coupling and the capability of sensing physical signals from the environment are critical elements among others for realizing functional neural circuits. When these two elements are involved in the dynamics of neural circuits, synchronization between circuits due to coupling or noise from the electronic sensory devices can occur. Therefore, in this paper, the effect of coupling and noise on the synchronization between two augmented thermosensitive FitzHugh–Nagumo neural circuits is investigated. It is shown that the fluctuation of temperature perceived by negative temperature coefficient thermistors yields a multiplicative noise exerting on the dynamics of the neural circuits. Contrary to what was expected, numerical results confirmed that the coupling suppresses synchronization while multiplicative noise facilitates synchronization. The mechanism underlying these phenomena is demonstrated by the phase portrait that peculiar to synchronizations and the first-return map to the Poincaré section. The intermittency behavior during the route to synchronization under different intensity of noise is also characterized, which would have significant value to the function neural circuit for self-adaption.