Tachykinin signaling defines distinct populations of glia in the enteric nervous system [scRNA-seq]

One of the largest populations of glia outside the brain is in the gut. These enteric glia are involved in many functions from intestinal peristalsis to immunity, yet it is unclear if there are defined types with distinct roles in homeostasis. Comparing glia from divergent microenvironments in the mouse intestine, we found that mucosal glia resembled microglia and macrophages, while muscularis glia resembled satellite glia. Tacr3, encoding the receptor for neuropeptide Neurokinin B (NKB), was enriched within muscularis glia associated with neuronal soma and was undetectable in extraintestinal glia. Genetic or pharmacological manipulation of NKB-TACR3 signaling disrupted establishment of enteric glial populations during postnatal development, and dynamically modulated intestinal motor behaviors in adult mice. Collectively, we delineate spatially, transcriptionally and functionally distinct populations of enteric glia, identify one as an unanticipated target of TACR3 antagonists in clinical use, and establish this pathway as necessary for enteric glial diversification and function. Overall design: To determine the transcriptomes of intraganglionic, connectives, and intramuscular glia, we performed single cell sequencing on FACS sorted glia from the ileal muscularis in Plp1eGFPTacr3IRESCre Rosa26tdTomato/+