Estradiol-Induced Enhancement of Object Memory Consolidation Involves NMDA Receptors and Protein Kinase A in the Dorsal Hippocampus of Female C57BL/6 Mice

This study examined the role of dorsal hippocampal NMDA receptors and PKA activation in 17β-estradiol (E 2 )-induced enhancement of object memory consolidation. Mice explored two identical objects during training, after which they immediately received intraperitoneal injections of 0.2 mg/kg E 2 , and bilateral dorsal hippocampal infusions of Vehicle, the NMDA receptor antagonist APV (2.5 μg/side), or the cAMP inhibitor Rp-cAMPS (18.0 μg/side). Retention was tested 48 hours later. The enhanced object memory and increased ERK phosphorylation observed with E 2 alone was reduced by APV and Rp-cAMPS, suggesting that estrogenic enhancement of object memory involves NMDA receptors and PKA activation within the dorsal hippocampus.