A long-lasting facilitation of hippocampal neurotransmission via a phospholipase A(2) signaling pathway

Phospholipase A,, which is linked to a protein kinase C pathway, hydrolyzes phosphatidylcholine into cis-unsaturated free fatty acids and lysophosphat idylcholine (lysoPC). The present study investigated the effect of the free fatty acids, such as arachidonic, oleic, linoleic, and linolenic acid, and lysoPC on neurotransmission by monitoring population spikes (PSs) from the granular cell layer of rat hippocampal slices. All the free fatty acids an d lysoPC examined here gradually increased PS amplitude to a different exte nt, the effect being evident 60 min after treatment. No significant synergi stic enhancement in the PS amplitude was not induced by arachidonic acid fo llowing oleic acid, linoleic acid or lysoPC. The results of the present stu dy, thus, demonstrate that phospholipase A(2)-linked free fatty acids and l ysoPC are employed in the sustained facilitation of hippocampal neurotransm ission, suggesting a significant role of a phospholipase A, signaling pathw ay in the neuroplasticity. (C) 2001 Elsevier Science Inc. All rights reserv ed.