Differential involvement of dopamine D1 receptor and MEK signaling pathway in the ventromedial prefrontal cortex in consolidation and reconsolidation of recognition memory.

We investigated MEK and D1 receptors in the ventromedial prefrontal cortex (vmPFC) in consolidation and reconsolidation of recognition memory in rats nonhabituated to the experimental context (NH) or with reduced arousal due to extensive prior habituation (H). The D1 receptor antagonist enhanced consolidation and impaired reconsolidation in NH but impaired consolidation with no effect on reconsolidation in H. The D1 receptor agonist had no effect on consolidation in either H or NH but impaired reconsolidation in both groups. The MEK inhibitor impaired consolidation and reconsolidation, regardless of arousal. Thus, vmPFC D1 receptors and MEK show differential involvement in memory and arousal.