The @entity3470 and canonical Wnt signaling pathways mediate the mnemonic effects of XXXX in the dorsal hippocampus.

@entity5732 @entity1420 @entity19 @entity27350 @entity3927 @entity3470 @entity13436 @entity1061 @entity18074
UNASSIGNED: Although much is known about the neural mechanisms responsible for the mnemonic effects of 17b-estradiol (E2 ), very little is understood about the mechanisms through which @entity1420 (P4 ) regulates memory. We previously showed that intrahippocampal infusion of P4 in ovariectomized female @entity19 enhances object recognition (OR) memory consolidation in a manner dependent on activation of dorsal hippocampal @entity13436 and @entity3470 signaling. However, the role of specific @entity1420 receptors (PRs) in mediating the effects of @entity1420 on memory consolidation and hippocampal cell signaling are unknown. Therefore, the goals of this study were to investigate the roles of membrane-associated and intracellular PRs in mediating hippocampal memory consolidation, and identify downstream cell signaling pathways activated by PRs. Membrane-associated PRs were targeted using bovine serum albumin-conjugated @entity1420 (BSA-P), and intracellular PRs ( @entity27350 , @entity1061 ) were targeted using the intracellular PR agonist @entity18074 . Immediately after OR training, ovariectomized @entity19 received bilateral dorsal hippocampal infusion of vehicle, P4 , BSA-P, or @entity18074 . OR memory consolidation was enhanced by P4 , BSA-P, and @entity18074 . However, only P4 and BSA-P activated @entity13436 and @entity3470 signaling. Furthermore, dorsal hippocampal infusion of the @entity13436 inhibitor @entity5732 blocked the memory-enhancing effects of BSA-P, but not @entity18074 . The intracellular PR antagonist @entity3927 blocked the memory-enhancing effects of @entity18074 , but not BSA-P. Interestingly, P4 robustly activated canonical Wnt signaling in the dorsal hippocampus, which is consistent with our recent findings that canonical Wnt signaling is necessary for OR memory consolidation. @entity18074 , but not BSA-P, also elicited a modest increase in canonical Wnt signaling. Collectively, these data suggest that activation of @entity13436 signaling is necessary for membrane-associated PRs to enhance OR, and indicate a role for canonical Wnt signaling in the memory-enhancing effects of intracellular PRs. This study provides the first evidence that membrane and intracellular PRs may employ different molecular mechanisms to enhance hippocampal memory.    2014 Wiley Periodicals, Inc.
