Dizocilpine-induced accuracy deficits in a visual signal detection task are not present following d-cycloserine administration in rats

The N-methyl-d-aspartate (NMDA) receptor system is thought to be underactive in schizophrenia which may contribute to attentional dysfunction in this disease. In a visual signal detection task that required discrimination of signaled-trials from trials with no signal, the NMDA receptor antagonist, dizocilpine (0.05 mg/kg), increased errors on non-signal trials. Co-administration of dizocilpine and 10.0 mg/kg d-cycloserine, a co-agonist at the glycine site on the NMDA receptor, significantly decreased the error rate on non-signal trials compared to dizocilpine alone. These results suggest that drugs targeting the glycine site may be beneficial for attenuating attentional deficits associated with an underactive NMDA receptor system.