Galanin is a widely distributed neuropeptide in the central nervous system (CNS), peripheral regions and endocrine system. Galanin interacts with 3 receptor subtypes, GalR1-3 G protein-coupled receptors inserted into the plasma membrane. Galanin has a role in energy homeostasis. Central injections of galanin to the amygdala led to food intake in rats. Galanin also acts in the CNS to inhibit neurotransmitter release, such as acetylcholine. Galanin has been implicated in numerous neurological conditions, including Alzheimer’s disease, depression, and epilepsy. A better understanding of the galinergic signalling pathways may uncover a source for therapeutics for conditions such as epilepsy.

Unlike human galanin, full-length porcine galanin contains only 29 amino acids and is C-terminally amidated. The first 15 residues are still highly conserved.  The best-recognized effect of galanin on the endocrine pancreas is the inhibition of insulin secretion in vitro and in vivo on multiple model systems, including rats, dogs, and mice. However, the same effect cannot be achieved at the same concentrations in human models with infusions of porcine galanin. Structural activity and point mutation studies show that the N-terminal (1-15) fragment is vital for the interaction/activation of the GAL receptor and the inhibition of insulin secretion.