PKC MEDIATED INTERACTION BETWEEN ARACHIDONIC-ACID AND METABOTROPIC GLUTAMATE RECEPTORS POTENTIATES SYNAPTIC TRANSMISSION IN THE RAT HIPPOCAMPAL SLICE

Perfusion of (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD, 50 mu M) caused a transient depression of the field excitatory postsyn aptic potential (fEPSP) recorded from the CA1 region of the rat hippoc ampal slice. Perfusion of arachidonic acid (10 mu M) alone had no effe ct on synaptic transmission, however, coperfusion of ACPD and arachido nic acid caused a slowly rising and persistent potentiation of the fEP SP. This effect was blocked by the selective protein kinase C (PKC) in hibitors hypericin (40 mu M) and chelerythrine (5 mu M). Neither methy l-arachidonic acid (10 mu M), nor oleic acid (10 mu M), mimicked arach idonic acid in producing the persistent potentiation. The results sugg est that arachidonic acid and ACPD interact to modulate synaptic trans mission by a process which relies on a synergistic, but indirect, acti vation of PKC.