Spike-adding and reset-induced canard cycles in adaptive integrate and fire models

TL;DR

This paper investigates adaptive integrate and fire models with piecewise linear dynamics, demonstrating the existence of bursting cycles with multiple resets, analyzing transitions between these cycles, and numerically computing their bifurcations, including canard explosions.

Contribution

It proves the existence of N-reset bursting cycles in AIF models and analyzes the transition mechanisms between different reset cycles, including canard phenomena.

Findings

Existence of N-reset bursting cycles for any integer N.

Transitions between N- and (N+1)-reset cycles are organized by canard cycles.

Numerical continuation reveals branches of bursting cycles and canard explosions.

Abstract

We study a class of planar integrate and fire (IF) models called adaptive integrate and fire (AIF) models, which possesses an adaptation variable on top of membrane potential, and whose subthreshold dynamics is piecewise linear (PWL). These AIF models therefore have two reset conditions, which enable bursting dynamics to emerge for suitable parameter values. Such models can be thought of as hybrid dynamical systems. We consider a particular slow dynamics within AIF models and prove the existence of bursting cycles with $N$ resets, for any integer $N$. Furthermore, we study the transition between $N$- and $(N+1)$-reset cycles upon vanishingly small parameter variations and prove (for $N=2$) that such transitions are organised by canard cycles. Finally, using numerical continuation we compute branches of bursting cycles, including canard-explosive branches, in these AIF models, by suitably recasting the periodic problem as a two-point boundary-value problem.