McDonald, K. O.; Yu, T.; Prabhu, A.; Aton, S.

Accurate and efficient memory processing is essential for survival. Recent work in human subjects and animal models has suggested that memory processing may differ in meaningful ways between males and females. In mice, contextual fear memory (CFM) encoding, consolidation, and recall have been well studied, and the mouse hippocampus and amygdala have been implicated in these processes. The present study addresses how the specific contribution of these brain regions to each stage CFM processing in female vs. male mice. We find that male and female mice show no differences in CFM recall, nor in sleep behavior in the hours following single-trial contextual fear conditioning (CFC), which is essential for CFM consolidation. However, females, but not males, show significantly increased expression of cFos in dorsal hippocampal CA1 and CA2 neurons during CFM encoding. On the other hand, males, but not females, show increased cFos expression among DG granule cells during CFM consolidation. These findings highlight the fact that the neurobiological underpinnings of memory processing may differ between males and females, even when recall performance is identical.