D2 dopamine receptor blockade immediately post-training enhances retention in hidden and visible platform versions of the water maze

Considerable evidence shows that post-training administration of dopamine agonists can enhance memory through actions on consolidation processes, but relatively little is known regarding the effects of dopamine antagonists on consolidation. These experiments investigated the effects of post-training systemic administration of the D2 receptor antagonist sulpiride on consolidation of memory for two versions of the Morris water maze task. Rats trained in either the hidden (spatial) or visible (cued) platform version received a subcutaneous injection of sulpiride or vehicle immediately following training. Retention testing 48 hr later revealed that relative to vehicle controls, sulpiride reduced platform latencies in both task versions, suggesting that like dopamine agonists, sulpiride can also have memory-enhancing effects.