Receptor blockade reveals a correspondence between hippocampal-dependent behavior and experience-dependent synaptic enhancement

This study examined the involvement of N-methyl-D-aspartate receptors (NMDA Rs) in experience-dependent synaptic plasticity. Rats chronically received an NMDA receptor antagonist (AP5) or saline (SAL) and were exposed to indiv idual cages (IC) or environmental enrichment (EC). AP5 impaired measures of hippocampal-dependent behavior and increased locomotor activity. Perforant path synaptic strength, measured in the in vitro hippocampal slice, was in creased and long-term potentiation (LTP) was decreased for EC+SAL animals. The experience-dependent effects on synaptic function were inhibited by dru g treatment. Measures of synaptic strength were correlated with hippocampal -dependent behavior and synaptic plasticity for EC animals. The results sug gest a relationship between hippocampal-dependent behavior and experience-d ependent modification of perforant path synaptic function through NMDAR act ivation. (C) 2000 Elsevier Science B.V. All rights reserved.