# An unusual potassium conductance protects Caenorhabditis elegans pharyngeal muscle rhythms against environmental noise

## TL;DR

A special potassium channel in C. elegans helps its feeding system stay stable despite environmental disturbances.

## Contribution

The discovery of a rapidly inactivating potassium conductance that enhances noise robustness in pharyngeal muscle rhythms.

## Key findings

- The unusual K+ conductance allows sustained depolarization until inhibitory input triggers repolarization.
- This mechanism protects pharyngeal muscle rhythms from early termination by hyperpolarizing noise.
- The model suggests similar mechanisms may enable switching between plateau and spiking behavior in other systems.

## Abstract

We present evidence from computational modeling that an unusual K+ conductance endows the pharyngeal feeding organ of the nematode Caenorhabditis elegans with critical robustness against environmental noise that could otherwise disrupt its feeding strategy. This unusual K+ conductance inactivates very rapidly, which allows the generation of a sustained depolarized plateau until an inhibitory input hyperpolarizes the muscle sufficiently to remove the inactivation, allowing the K+ conductance to fully repolarize the muscle.

The nematode Caenorhabditis elegans feeds by rhythmic contraction and relaxation of a neuromuscular organ called the pharynx, which draws in and filters water and bacterial food. This behavior is driven by myogenic plateau potentials, long-lasting depolarizations of the pharyngeal muscle, which are timed by neuronal input from a dedicated pharyngeal nervous system. While the timing of these plateaus’ initiation has received significant attention, their mechanisms of termination remain incompletely understood. In particular, it is unclear how plateaus resist early termination by hyperpolarizing current noise. Here, we present a computational model of pharyngeal plateaus against a noisy background. We propose that an unusual, rapidly inactivating potassium conductance confers exceptional noise robustness on the system. We further investigate the possibility that a similar mechanism in other systems permits switching between plateau and spiking behavior under noisy conditions.