Persistent prelimbic cortex activity contributes to enhanced learned fear expression in females
- Georgina E. Fenton1,
- Amelia K. Pollard2,
- David M. Halliday3,
- Rob Mason4,
- Timothy W. Bredy5 and
- Carl W. Stevenson1,6
- 1School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom
- 2School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom
- 3Department of Electronics, University of York, Heslington, York YO10 5DD, United Kingdom
- 4School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, United Kingdom
- 5Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
Abstract
Anxiety disorders, such as post-traumatic stress, are more prevalent in women and are characterized by impaired inhibition of learned fear and medial prefrontal cortex (mPFC) dysfunction. Here we examined sex differences in fear extinction and mPFC activity in rats. Females showed more learned fear expression during extinction and its recall, but not fear conditioning. They also showed more spontaneous fear recovery and more contextual fear before extinction and its recall. Moreover, enhanced learned fear expression in females was associated with sustained prelimbic (PL) cortex activity. These results suggest that sex differences in learned fear expression may involve persistent PL activation.
Footnotes
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↵6 Corresponding author
E-mail carl.stevenson{at}nottingham.ac.uk
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Freely available online through the Learning & Memory Open Access option.
- Received October 7, 2013.
- Accepted November 4, 2013.
This article, published in Learning & Memory, is available under a Creative Commons License (Attribution 3.0 Unported), as described at http://creativecommons.org/licenses/by/3.0/.
