Galanin receptor 1 (GALR1) mediates the effects of the peptide galanin in a wide variety of tissues. Unlike GALR2, the primary signaling mechanism of GALR1 is by inhibiting adenylate cyclase through Gi. GALR1 regulates the GnRH neuroendocrine axis with its expression in POMC neurons. Pathogens like E. coli can cause diarrhea by increasing expression of Galanin Receptor 1 in the epithelial cells lining the colon, resulting in increased secretion of colonocyte chloride and fluid. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804