The effect of galanin on wide-dynamic range neuron activity in the spinal dorsal horn of rats

The present study investigated the effect of galanin on wide-dynamic range (WDR) neuron activity in the dorsal horn of the spinal cord of rats. The ev oked discharge of WDR neurons was elicited by transdermic electrical stimul ation applied on the ipsilateral hindpaw of rats. Galanin was administered directly on the spinal dorsal surface of L3-L5. The evoked discharge freque ncy of the WDR neurons decreased significantly after the administration of galanin and the effect lasted for more than 30 min. Furthermore, the inhibi tory effect of galanin on the evoked discharge frequency of WDR neurons was blocked by following administration of the galanin antagonist galantide, i ndicating that the inhibitory effect of galanin on the activity of WDR neur ons was induced by activating galanin receptors in the dorsal horn of the s pinal cord. The results suggest that galanin has an inhibitory role in the transmission of presumed nociceptive information in the dorsal horn of the spinal cord in rats. (C) 2001 Elsevier Science BN. All rights reserved.