ARACHIDONIC-ACID METABOLITES AND THE SYNAPTIC POTENTIATION EVOKED BY ACTIVATION OF METABOTROPIC GLUTAMATE RECEPTORS

We have previously shown that coapplication of arachidonic acid (10 mu M) and (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD, 50 mu M) evokes an enhancement of synaptic transmission in the CA1 region o f the rat hippocampal slice. Here we have investigated whether the met abolites of arachidonic acid are implicated in this potentiation. Incl usion of the cyclo-oxygenase inhibitor indomethacin (10 mu M) did not block the potentiation induced by coapplication of arachidonic acid an d ACPD. However the presence of either the cyclo-, lipo- and epoxygena se inhibitor 5,8,11,14-eicosatetraynoic acid (ETYA, 20 mu M), or the l ipoxygenase inhibitor nordihydroguaiaretic acid (10 mu M), prevented t he long-lasting enhancement. The results suggest that the lipoxygenase and epoxygenase metabolites of arachidonic acid may be involved in th e induction of this form of synaptic potentiation. (C) 1998 Elsevier S cience B.V.