Abstract

NEUROPEPTIDE GALANIN IN HEALTH AND DISEASE: A REVIEW

Dr. Asha G, *Dr. Venkata Bharat Kumar Pinnelli, Dr. Jayashankar CA, Dr. Shrabani Mohanty, Dr. Raghavendra DS

Abstract

Galanin is a regulatory neuropeptide, widely distributed in the nervous system and gut, that acts via three subtypes of G protein-coupled receptors, named galanin receptor 1 (GAL-R1), GAL-R2 and GAL-R3. Galanin and its receptors are expressed in the hypothalamic paraventricular and supraoptic nuclei, anterior pituitary and adrenal medulla. Galanin is widely expressed in the central and peripheral nervous system, endocrine system and co-exists with a number of classical neurotransmitters. Galanin mediates widespread about partially overlapping distribution in the brain, and by partially different transduction mechanisms. The GAL-R1 is coupled to Gi/Go types of G-proteins and mediates inhibitory actions of galanin, GAL-R3 is coupled to Gi/Go-proteins and mediates a hyperpolarization response. The GAL-R2, mainly mediates stimulatory effects of galanin on neurotransmitter release, since it is coupled to the phospholipase C pathway, intracellular Ca2+ mobilization and Ca2+-dependent Cl− channel activation. Galanin is involved in the control of feeding, alcohol intake, seizure threshold, cognitive performance and control of pain threshold. This review aims to summarize the current data of the importance of the galanin and galanin receptor subtypes and their involvement in different physiological and pathological functions.

Keywords: (3-6 words): Galanin, Neuropeptide, G protein-coupled receptor, Hypothalamus.