A Neural Circuit for Gut-Induced Reward

• Published in: Cell 2018-10, Vol.175 (3), p.665-678.e23
• Main Authors: Han, Wenfei, Tellez, Luis A., Perkins, Matthew H., Perez, Isaac O., Qu, Taoran, Ferreira, Jozelia, Ferreira, Tatiana L., Quinn, Daniele, Liu, Zhong-Wu, Gao, Xiao-Bing, Kaelberer, Melanie M., Bohórquez, Diego V., Shammah-Lagnado, Sara J., de Lartigue, Guillaume, de Araujo, Ivan E.
• Format: Article
• Language: English
• Subjects: Afferent Pathways - metabolism; Afferent Pathways - physiology; Animals; dopamine; Dopamine - metabolism; Dopaminergic Neurons - physiology; Glutamic Acid - metabolism; gut-brain axis; Intestines - innervation; Intestines - physiology; Male; Mice; Mice, Inbred C57BL; Optogenetics; Reward; Substantia Nigra - physiology; vagus nerve; Vagus Nerve - physiology
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/j.cell.2018.08.049

The gut is now recognized as a major regulator of motivational and emotional states. However, the relevant gut-brain neuronal circuitry remains unknown. We show that optical activation of gut-innervating vagal sensory neurons recapitulates the hallmark effects of stimulating brain reward neurons. Specifically, right, but not left, vagal sensory ganglion activation sustained self-stimulation behavior, conditioned both flavor and place preferences, and induced dopamine release from Substantia nigra. Cell-specific transneuronal tracing revealed asymmetric ascending pathways of vagal origin throughout the CNS. In particular, transneuronal labeling identified the glutamatergic neurons of the dorsolateral parabrachial region as the obligatory relay linking the right vagal sensory ganglion to dopamine cells in Substantia nigra. Consistently, optical activation of parabrachio-nigral projections replicated the rewarding effects of right vagus excitation. Our findings establish the vagal gut-to-brain axis as an integral component of the neuronal reward pathway. They also suggest novel vagal stimulation approaches to affective disorders. [Display omitted] •Critical role for the vagal gut-to-brain axis in motivation and reward•Optogenetic stimulation of the vagal gut-to-brain axis produces reward behaviors•Asymmetric brain pathways of vagal origin mediate motivation and dopamine activity•Gut-innervating vagal sensory neurons are major components of the reward circuitry A gut-to-brain neural circuit establishes vagal neurons as an essential component of the reward neuronal pathway, linking sensory neurons in the upper gut to striatal dopamine release.