Fenton Georgina E, Halliday David M, Mason Rob, Bredy Timothy W, Stevenson Carl W
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
Department of Electronics, University of York, Heslington, York YO10 5DD, UK.
Neurobiol Learn Mem. 2016 Nov;135:66-72. doi: 10.1016/j.nlm.2016.06.019. Epub 2016 Jun 21.
Sex differences in learned fear expression and extinction involve the medial prefrontal cortex (mPFC). We recently demonstrated that enhanced learned fear expression during auditory fear extinction and its recall is linked to persistent theta activation in the prelimbic (PL) but not infralimbic (IL) cortex of female rats. Emerging evidence indicates that gamma oscillations in mPFC are also implicated in the expression and extinction of learned fear. Therefore we re-examined our in vivo electrophysiology data and found that females showed persistent PL gamma activation during extinction and a failure of IL gamma activation during extinction recall. Altered prefrontal gamma oscillations thus accompany sex differences in learned fear expression and its extinction. These findings are relevant for understanding the neural basis of post-traumatic stress disorder, which is more prevalent in women and involves impaired extinction and mPFC dysfunction.
习得性恐惧表达和消退中的性别差异涉及内侧前额叶皮质（mPFC）。我们最近证明，在听觉恐惧消退及其回忆过程中增强的习得性恐惧表达与雌性大鼠前边缘（PL）而非下边缘（IL）皮质中持续的θ波激活有关。新出现的证据表明，mPFC中的γ振荡也与习得性恐惧的表达和消退有关。因此，我们重新检查了我们的体内电生理数据，发现雌性大鼠在消退过程中表现出持续的PLγ波激活，而在消退回忆过程中ILγ波激活失败。前额叶γ振荡的改变因此伴随着习得性恐惧表达及其消退中的性别差异。这些发现对于理解创伤后应激障碍的神经基础具有重要意义，创伤后应激障碍在女性中更为普遍，并且涉及消退受损和mPFC功能障碍。
