Intra-periaqueductal grey injection of galanin increases the nociceptive response latency in rats, an effect reversed by naloxone.

The nociceptive response latencies were increased significantly after intra-periaqueductal grey (PAG) administration of 1.0 or 3.0 nmol of galanin, but not 0.3 nmol, in rats. The effect of galanin was attenuated by following injection of 5.5 nmol of naloxone into PAG. These results indicate an anti-nociceptive role of galanin, and a possible interaction between galanin and opioid peptides in PAG in rats. Copyright 1999 Elsevier Science B.V.