Ion channels of the intestinal hyperpolarizing action potential in nematodes

The defaecation motor program in nematodes is controlled by the intestinal central pattern generator, coupled with propagating calcium waves and electrical membrane potential oscillations. Recent electrophysiological experiments in lieterorhabdins megidis have indicated that the intestinal cells of nematodes produce unusual all-or-none hyperpolarisation 'action potential' (HAP). HAP resembles the action potential generation in regular excitable tissues, neurons and myocytes, having the reversed polarity of current and voltage. It can be considered that rhythmic electrical potential generation in the intestinal cells is based on the cooperation of voltage-gated ion channels. Here we combined our electrophysiological study with molecular-genetics of the nematode intestine and recent single-cell RNA-seq open-access data of Caenorhabditis elegans. Single-cell RNA-seq data confirm the unique spectrum of the ion channel expression in the gut cells, which is highly distinct from other nematode tissues. We have compared electrophysiological data with the channel expression data from nematode tissues implementing regular action potential and HAP to find ion channel candidates that can fit HAP model.