In the present study, the effects of phosphatidylserine (BC-PS) on hippocampal synaptic transmission were evaluated. Extracellular potentials evoked by low-frequency stimulation (0.2 Hz) of the perforant path (PP) were recorded from the granule cell layer of the dentate gyrus in 400 microns hippocampal slices. Slices were perfused with either BC-PS alone (10 microM) or BC-PS in combination with DL-2-amino-5-phosphonovaleric acid (APV, 20 microM), or after previous perfusion with dizocilpine (MK-801, 10 microM). BC-PS significantly potentiated PP-evoked responses (mean percent increase +/- SEM, 108 +/- 18%), an effect that was blocked by perfusion of MK-801, but not APV. The increase in hippocampal synaptic efficacy produced by BC-PS is discussed in terms of N-methyl-D-aspartate receptors (NMDA) and the associated channels.