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 17 beta-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 mu g/side), or the cAMP inhibitor Rp-cAMPS (18.0 mu g/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.