ACTIONS OF KAVAIN AND DIHYDROMETHYSTICIN ON IPSAPIRONE-INDUCED FIELD POTENTIAL CHANGES IN THE HIPPOCAMPUS

The kava-pyrones kavain and dihydromethysticin are constituents of Pip er methysticum which possess muscle relaxant, anticonvulsant, analgesi c and anxiolytic properties. In the present study the effect of both k ava-pyrones were tested on held potential changes induced by the serot onin-1A agonist ipsapirone in the area CA1 and CA3 of the hippocampal slice preparation of guinea pigs. Ipsapirone induced positive field po tential changes which were decreased in amplitude by the serotonin-1A antagonist NAN. The ipsapirone response was reduced by extracellular a dministration of kavain and dihydromethysticin in a dose-dependent man ner down to 22.2 and 33.6%, respectively. It is suggested that kavain and dihydromethysticin modulate serotonin-1A receptor activity which m ay be of importance in the anti-anxiety action of kava-pyrones. (C) 19 97 by John Wiley Sons, Ltd.