title: Persistent prelimbic cortex activity contributes to enhanced learned fear expression in females.
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.
authors.affiliation: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom.
authors.forename: Georgina E
authors.initials: GE
authors.lastname: Fenton
authors.forename: Amelia K
authors.initials: AK
authors.lastname: Pollard
authors.forename: David M
authors.initials: DM
authors.lastname: Halliday
authors.forename: Rob
authors.initials: R
authors.lastname: Mason
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Bredy
authors.forename: Carl W
authors.initials: CW
authors.lastname: Stevenson
mesh_terms: D000161:Acoustic Stimulation; D000704:Analysis of Variance; D000818:Animals; D001307:Auditory Perception; D003213:Conditioning, Psychological; D004567:Electrodes, Implanted; D004597:Electroshock; D005108:Extinction, Psychological; D005239:Fear; D005260:Female; D046352:Freezing Reaction, Cataleptic; D008297:Male; D011939:Mental Recall; D017397:Prefrontal Cortex / Q000502:physiology*; D051381:Rats; D012727:Sex Characteristics; D013826:Theta Rhythm; D013997:Time Factors