Attenuation of scopolamine-induced deficits in pigeons' attention to delayed matching-to-sample cues by D-cycloserine

The ability of D-cycloserine to improve delayed matching accuracy and to reverse scopolamine-induced deficits in delayed matching-to-sample performance in pigeons was investigated. Dose levels were 0, 2, 4 and 6 mg/kg of D-cycloserine and 0.025 mg/kg of scopolamine. Drugs were administered via the intraperitoneal cavity at a constant volume of 1 ml/kg. Administration of scopolamine impaired matching accuracy across all retention intervals. D-Cycloserine attenuated the scopolamine-induced deficit. Higher order analyses revealed that initial discriminability, but not rate of forgetting, was affected by scopolamine and D-cycloserine administration. These results indicate that D-cycloserine is capable of reversing scopolamine-induced deficits in matching accuracy and suggest that a synergistic relationship may exist between the cholinergic and glutamatergic systems.