Actions of Kavain and Dihydromethysticin on Ipsapirone-Induced Field Potential Changes in the Hippocampus

Abstract

The kava‐pyrones kavain and dihydromethysticin are constituents of Piper methysticum which possess muscle relaxant, anticonvulsant, analgesic and anxiolytic properties. In the present study the effect of both kava‐pyrones were tested on field potential changes induced by the serotonin‐1A agonist ipsapirone in the area CA1 and CA3 of the hippocampal slice preparation of guinea pigs. Ipsapirone induced positive field potential changes which were decreased in amplitude by the serotonin‐1A antagonist NAN. The ipsapirone response was reduced by extracellular administration of kavain and dihydromethysticin in a dose‐dependent manner down to 22·2 and 33·6%, respectively. It is suggested that kavain and dihydromethysticin modulate serotonin‐1A receptor activity which may be of importance in the anti‐anxiety action of kava‐pyrones. © 1997 John Wiley & Sons, Ltd.