Vagal sensory neurons and gut-brain signaling

• Published in: Current opinion in neurobiology Vol. 62; pp. 133 - 140
• Main Authors: Yu, Chuyue D, Xu, Qian J, Chang, Rui B
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2020
• Subjects: Brain; Gastrointestinal Microbiome; Sensory Receptor Cells; Signal Transduction; Vagus Nerve
• ISSN: 0959-4388; 1873-6882
• DOI: 10.1016/j.conb.2020.03.006

• The vagus nerve is a crucial link between gut signals and the brain regulating various functions such as energy homeostasis, digestion, immune responses, reward, memory, and cognition.• Vagal afferents form different terminal endings in the gut, including direct synapses with some enteroendocrine cells named neuropods.• Vagal sensory neurons monitor ingested nutrients and water from the gut and provide fast regulation of food intake and fluid homeostasis.• Afferents in the left and the right vagus nerve exhibit asymmetric anatomical projections in the brain, for example, a reward gut-to-brain circuit is specifically formed by right vagal afferents. Our understanding of the gut system has been revolutionized over the past decade, in particular regarding its role in immune control and psychological regulation. The vagus nerve is a crucial link between gut and brain, transmitting diverse gut-derived signals, and has been implicated in many gastrointestinal, neurological, and immunological disorders. Using state-of-the-art technologies including single-cell genomic analysis, real-time neural activity recording, trans-synaptic tracing, and electron microscopy, novel physiological functions of vagal gut afferents have been uncovered, and new gut-to-brain pathways have been revealed. Here, we review the most recent findings on vagal sensory neurons and the gut-brain signaling, focusing on the anatomical basis and the underlying molecular and cellular mechanisms. Such new discoveries explain some of the old puzzling problems and also raise new questions in this exciting and rapidly growing field.