Multimodal transition and excitability of a neural oscillator

TL;DR

This paper investigates the response dynamics of the Morris-Lecar neural model to periodic stimuli, revealing a universal multimodal transition linked to bistability and resonant behavior in neurons.

Contribution

It demonstrates the existence of a multimodal transition in the Morris-Lecar model, connecting it to similar phenomena in Hodgkin-Huxley neurons and experimental data.

Findings

Multimodal transition occurs between odd and all modes.

Transition is located between 2:1 and 3:1 locked-in regions.

Transition coincides with bistability of 2:1 and 3:1 states.

Abstract

We analyze the response of the Morris-Lecar model to a periodic train of short current pulses in the period-amplitude plane. For a wide parameter range encompassing both class 2 and class 3 behavior in Hodgkin's classification there is a multimodal transition between the set of odd modes and the set of all modes. It is located between the 2:1 and 3:1 locked-in regions. It is the same dynamic instability as the one discovered earlier in the Hodgkin-Huxley model and observed experimentally in squid giant axons. It appears simultaneously with the bistability of the states 2:1 and 3:1 in the perithreshold regime. These results imply that the multimodal transition may be a universal property of resonant neurons.