Journal
NEUROBIOLOGY OF LEARNING AND MEMORY
Volume 123, Issue -, Pages 117-124Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.nlm.2015.05.009
Keywords
Fear conditioning; Fear extinction; Spontaneous recovery; Sex differences; ERK
Funding
- [245315]
- [26860912]
- Grants-in-Aid for Scientific Research [26860912] Funding Source: KAKEN
Ask authors/readers for more resources
Stress-related disorders, such as post-traumatic stress disorder (PTSD) and panic disorders, are disproportionately prevalent in females. However, the biological mechanism underlying these sex differences in the prevalence rate remains unclear. In the present study, we examined sex differences in fear memory, fear extinction, and spontaneous recovery of fear. We investigated the presence of sex differences in recent and remote fear memory in mice using contextual fear conditioning, as well as sex differences in spontaneous recovery of fear memory using a consecutive fear extinction paradigm. We examined the number of fear extinction days required to prevent spontaneous recovery of fear in either sex. We investigated whether ovariectomy affected fear extinction and spontaneous recovery. We also measured the activation of extracellular signal-regulated kinase (ERK) 1 and 2 in the dorsal hippocampus and the medial prefrontal cortex following fear extinction sessions. In our results, we found no sex difference in recent or remote fear memory. However, females required more fear extinction sessions compared to males to prevent spontaneous recovery. Within-extinction freezing also differed between males and females. Moreover, females required more extinction sessions than males to increase ERK2 phosphorylation in the dorsal hippocampus. Our data suggest that contextual fear extinction was unstable in females compared to males and that such sex differences may be related to the ERK2 phosphorylation in the hippocampus. (C) 2015 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available