Cellular switches orchestrate rhythmic circuits

TL;DR

This paper demonstrates that a cellular switching mechanism, involving a slow negative conductance, enables small inhibitory circuits to be reconfigurable, robust, and externally controllable, enhancing understanding of rhythmic motor functions.

Contribution

It introduces the cellular switch mechanism, mediated by slow negative conductance, as a key factor in reconfiguring and controlling rhythmic circuits, which was previously overlooked.

Findings

Cellular switch makes circuits reconfigurable and robust.

Without the switch, circuits are fragile and hard to control.

The slow negative conductance is crucial for neuromodulation studies.

Abstract

Small inhibitory neuronal circuits have long been identified as key neuronal motifs to generate and modulate the coexisting rhythms of various motor functions. Our paper highlights the role of a cellular switching mechanism to orchestrate such circuits. The cellular switch makes the circuits reconfigurable, robust, adaptable, and externally controllable. Without this cellular mechanism, the circuits rhythms entirely rely on specific tunings of the synaptic connectivity, which makes them rigid, fragile, and difficult to control externally. We illustrate those properties on the much studied architecture of a small network controlling both the pyloric and gastric rhythms of crabs. The cellular switch is provided by a slow negative conductance often neglected in mathematical modeling of central pattern generators. We propose that this conductance is simple to model and key to computational studies of rhythmic circuit neuromodulation.