Phospholipase A2-induced changes in AMPA receptor: an autoradiographic study.

The expression of long-term potentiation and learning of a classical conditioning task increase 3H]-AMPA binding in hippocampus. Phospholipase A2 (PLA2) has been proposed to underly these changes, as PLA2 treatment of membrane preparations increases the affinity of AMPA receptors for agonists. We demonstrate here that preincubation of thin (10 microns) frozen rat brain sections with exogenous PLA2 and calcium at physiological temperature changes the binding properties of AMPA receptors. Quantitative autoradiography reveals that PLA2-treatment produces a differential increase in 3H]-AMPA binding across brain regions. The same treatment also decreases the binding of an antagonist (3H]-CNQX) throughout the brain. We propose that PLA2 treatment results in a modification of the AMPA receptors which is regionally specific, probably due to different AMPA receptor subunit compositions.