The nucleus accumbens (NAcb), a basal forebrain structure implicated in drug-mediated reward, receives afferents from a variety of limbic and cortical structures, including the prefrontal cortex, the amygdala, the entorhinal cortex, and the subicular complex. In the present study, monosynaptic projections from the lateral entorhinal cortex (lateral perforant path) to the NAcb are shown to display sustained increases in field EPSP magnitudes following high-frequency stimulation of the perforant path in anesthetized rats. By contrast, stimulation of the medial aspect of the perforant path, although capable of evoking responses in the dentate gyrus, produced no observable synaptic responses within the nucleus accumbens. Intra-accumbens administration of (±)-CPP (-3-(2-carboxypiperazin-4-yl)- propyl-1-phosphonic acid), a selective competitive NMDA receptor antagonist, blocked both short-term potentiation and long-term potentiation (LTP). Thus afferents from the entorhinal cortex to the NAcb display NMDA-receptor- dependent synaptic potentiation that appears similar to NMDA-receptor- dependent LTP observed at other targets of the perforant path, such as the hippocampal formation.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Sep 1998|
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