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

Considerable evidence shows that post-training administration of dopamine a gonists 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 consoli dation of memory for two versions of the Morris water maze task. Rats train ed in either the hidden (spatial) or visible (cued) platform version receiv ed a subcutaneous injection of sulpiride or vehicle immediately following t raining. Retention testing 48 hr later revealed that relative to vehicle co ntrols, sulpiride reduced platform latencies in both task versions, suggest ing that like dopamine agonists, sulpiride can also have memory-enhancing e ffects.