EFFECT OF BROMOPHENACYL BROMIDE, A PHOSPHOLIPASE-A2 INHIBITOR, ON THE INDUCTION AND MAINTENANCE OF LTP IN HIPPOCAMPAL SLICES

The effect of bromophenacyl bromide (BPB), a phospholipase A2 (PLA2) inhibitor, on both the induction and the maintenance of long-term potentiation (LTP) was investigated in field CA1 of the hippocampal slice preparation. One hour of BPB application (50-mu-M) caused a large reduction in the magnitude of LTP induced by a theta burst stimulation (TBS) paradigm. BPB had no significant effect on either the degree of paired-pulse facilitation or the amount of pre-established LTP. Furthermore, the facilitation of postsynaptic responses occurring during TBS and in the first minute following TBS was not reduced by the PLA2 inhibitor. These results indicate that the inhibition of LTP produced by BPB is not due to an effect of the drug on a physiological event that triggers LTP. The data also suggest that PLA2 activation plays a critical role in the expression of LTP, but is not required for the maintenance of the potentiation.