Galanin, also referred to as Gal or Galn, is a 30 amino acid neuropeptide (29 in rodents) which was first isolated from porcine intestine in 1983 (1). It is synthesized as part of a larger propeptide which is proteolytically processed to release the mature neuropeptide. Galanin is highly conserved across species and has a widespread presence in the periphery and the central nervous system, including brain, spinal cord, and gastrointestinal tract. The effects of this neuropeptide are mediated through three G protein coupled galanin receptors (2, 3).
Galanin has been implicated in many biologically diverse functions including arousal/sleep regulation, nociception, cognition, feeding, reproduction, osmotic homeostasis, glucose metabolism, and regulation of mood (3, 4).
Several human diseases, including Alzheimer’s disease, epilepsy, diabetes mellitus and mood disorders like anxiety and depression are associated with the disturbance of the galaninergic system (2, 3).