Galanin acts as a trophic factor to the central and peripheral nervous systems

The neuropeptide galanin is widely, but not ubiquitously, expressed in the adult nervous system. Its expression is markedly upregulated in many neuronal tissues after nerve injury or disease. Over the last 10 years we have demonstrated that the peptide plays a developmental survival role to subsets of neurons in the peripheral and central nervous systems with resulting phenotypic changes in neuropathic pain and cognition. Galanin also appears to play a trophic role to adult sensory neurons following injury, via activation of GalR2, by stimulating neurite outgrowth. Furthermore, galanin also plays a neuroprotective role to the hippocampus following excitotoxic injury, again mediated by activation of GalR2. In summary, these studies demonstrate that a GalR2 agonist might have clinical utility in a variety of human diseases that affect the nervous system.