Retrosplenial cortex 5-HT2A receptors critically contribute to recognition memory processing.

The anterior retrosplenial cortex (aRSC) functions as a hub that integrates multimodal sensory inputs into associative recognition memories. Although the aRSC receives dense serotonergic projections from the raphe nuclei, the role of serotonin in its function remains poorly understood. Among serotonergic receptors, 5-HT2A receptors (5-HT2ARs) are highly expressed in cortical regions, including the aRSC, and have been implicated in the modulation of cognitive processes. Based on our previous work demonstrating the involvement of the aRSC in recognition memory, here we investigated the contribution of 5-HT2ARs (memory) during different phases of the object recognition (OR) task in rats. We found that selective blockade of 5-HT2ARs in the aRSC differentially affected acquisition, consolidation, and retrieval. These findings identify 5-HT2ARs in the aRSC as critical modulators of recognition memory processing and suggest that their dysregulation could contribute to cognitive impairments observed in conditions such as Alzheimer's disease.