Galanin

Galanin is a neuropeptide encoded by the GAL gene, that is widely expressed in the brain, spinal cord, and gut of humans as well as other mammals. Galanin signaling occurs through three G protein-coupled receptors.

The functional role of galanin remains largely unknown; however, galanin is predominately involved in the modulation and inhibition of action potentials in neurons. Galanin has been implicated in many biologically diverse functions, including: nociception, waking and sleep regulation, cognition, feeding, regulation of mood, regulation of blood pressure, it also has roles in development as well as acting as a trophic factor. Galanin neurons in the medial preoptic area of the hypothalamus may govern parental behaviour. Galanin is linked to a number of diseases including Alzheimer's disease, epilepsy as well as depression, eating disorders and cancer. Galanin appears to have neuroprotective activity as its biosynthesis is increased 2-10 fold upon axotomy in the peripheral nervous system as well as when seizure activity occurs in the brain. It may also promote neurogenesis.