Brainstem structures such as the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus nerve (DMNX) are essential for the digestive function of the stomach. A large number of neurotransmitters including glutamate and gamma-aminobutyric acid (GABA) are involved in the central control of gastric functions. However, the neuropeptidergic systems implicated in this process remain undetermined. Nesfatin-1 was recently identified as a neuropeptide cleaved from the N-terminal part of NEFA/nucleobindin 2 precursor (NUCB2). Central administration of this neuropeptide inhibits food consumption and gastroduodenal motility in rodents. Interestingly, the NTS and the DMNX contain a dense population of NUCB2/nesfatin-1 cell bodies. These observations led us to investigate the possible involvement of NUCB2/nesfatin-1 neurons in the brainstem neuronal pathways that modulate gastric functions. We observed an activation of NTS NUCB2/nesfatinergic neurons after gastric distention in rats. In addition, we found that several NTS NUCB2/nesfatinergic neurons were GABAergic. Finally, when fluorogold was injected at the stomach level, many retrogradely labeled neurons were observed in the DMNX which were also positive for NUCB2/nesfatin-1. Taken together, these observations suggest for the first time that NUCB2/nesfatin-1 neurons of the NTS are sensitive to gastric distension and then may contribute to the satiety signal.
Keywords: ChAT; DMNX; DVC; FG; Food intake; GABA; GAD67; GD; GI; GIN; Gastric distension; LPS; NTS; NUCB2; NUCB2/nesfatin-1; Nucleobindin-2; choline acetyltransferase; dorsal motor nucleus of the vagus nerve; dorsal vagal complex; eGFP-expressing Inhibitory Neurons; fluorogold; gamma amino-butyric acid; gastric distension; gastro-intestinal; glutamic acid decarboxylase 67; lipopolysaccharide; nucleus of the solitary tract.
© 2013.