Lateralized nodose ganglia gene expression implicates cholecystokinin receptors in interoceptive reward signaling

The vagus nerves are important carriers of sensory information from the viscera to the central nervous system. Emerging evidence suggests that sensory signaling through the right, but not the left, vagus nerve evokes striatal dopamine release and reinforces appetitive behaviors. However, the extent to which differential gene expression within vagal sensory neurons contributes to this asymmetric reward-related signaling remains unknown. Here, we use single-cell RNA sequencing to identify genes that are differentially expressed between the left and right nodose ganglia (NG) to identify candidate genes likely to contribute to vagus-mediated reward signaling. We find that a group of neurons expressing Chrna3 (nicotinic acetylcholine receptor subunit 3) and Cckar (cholecystokinin A receptor) is preferentially expressed in the right NG of both rats and mice. This result suggests that differential expression of gut-innervating nutrient sensors in NG neurons may contribute to asymmetric encoding of interoceptive rewards by the vagus nerves.