Galanin (GAL)

Galanin is formed by the cleavage of a prepropeptide encoded by a gene known as GAL. It is involved in a number of physiological processes such as regulation of food intake, metabolism and reproduction, regulation of neurotransmitter and hormone release, nociception, intestinal contraction and secretion, and more recently in nervous system development and response to injury. This wide diversity of action is mediated by several galanin receptor subtypes.Galanin is predominantly an inhibitory, hyperpolarizing neuropeptide and as such inhibits neurotransmitter release. Galanin is often co-localized with classical neurotransmitters such as acetylcholine, serotonin and norepinephrine and also with other neuromodulators such as Neuropeptide Y, Substance P and Vasoactive intestinal peptide.