Abstract
The vagus nerve innervates many organs, and most, if not all, of its motor fibers are cholinergic. However, no one knows its organizing principles-whether or not there are dedicated neurons with restricted targets that act as "labeled lines" to perform certain functions, including two opposing ones (gastric contraction versus relaxation). By performing unbiased transcriptional profiling of DMV cholinergic neurons, we discovered seven molecularly distinct subtypes of motor neurons. Then, by using subtype-specific Cre driver mice, we show that two of these subtypes exclusively innervate the glandular domain of the stomach where, remarkably, they contact different enteric neurons releasing functionally opposing neurotransmitters (acetylcholine versus nitric oxide). Thus, the vagus motor nerve communicates via genetically defined labeled lines to control functionally unique enteric neurons within discrete subregions of the gastrointestinal tract. This discovery reveals that the parasympathetic nervous system utilizes a striking division of labor to control autonomic function.