Prototypical pacemaker neurons interact with the resident microbiota

Here, we discover prototypical pacemaker neurons in the ancient cnidarian Hydra and provide evidence for a direct interaction of these neurons with the commensal microbiota. We uncover a remarkable gene-expression program conservation between the Hydra pacemaker neurons and pacemaker cells in Caenorhabditis elegans and the mammalian gut. We suggest that prototypical pacemaker cells emerged as neurons using components of innate immunity to interact with the microbial environment and ion channels to generate rhythmic contractions. The communication of pacemaker neurons with the microbiota represents a mechanistic link between the gut microbiota and gut motility. Our discoveries improve the understanding of the archetypical properties of the enteric nervous systems, which are perturbed in human dysmotility-related conditions.