Sex differences and fear extinction

Extinction of conditioned fear in animals is the explicit model of behavior therapy for human anxiety disorders, including panic disorder, obsessive-compulsive disorder and post-traumatic stress disorder. This type of learning depends on communication between the medial prefrontal cortex (mPFC) and the amygdale. Mental illnesses such as PTSD as a result of disruption of this circuit. Different studies showed that PTSD in women is higher than in men. One of the reasons of such difference are gonadal steroids so that based on preclinical and clinical ovarian hormones not only have an important role in modulation of fear and anxiety and fear extinction in women, but also are targets for the development of novel therapeutics for stress related disorders. Women in the luteal phase (high circulating estrogen) of the menstrual cycle have stronger extinction recall compared with women in the early follicular phase or on oral contraceptives (low circulating estrogen). In addition to estrogen, progesterone and its neuroactive metabolite, allopregnanolone, have been shown to modulate anxiety and fear. Progesterone treatment in intact female rats facilitates extinction recall. The other reason for this difference is returned to neural processes underlying successful or failed extinction that thought to be sex-specific. Discriminate these differences will be useful for exposure-based clinical therapies, which are similar in premise to fear extinction and which are primarily used to treat disorders that are more common in women than in men. The lack of a discernible relationship between IL-BLA structure and extinction retrieval in female animals suggests that variability in freezing during extinction retrieval in female animals. On the other hand, freezing is not an incomplete indicator of fear in female animals. This distinction could have implications for identifying sex-specific risk factors for PTSD. Generally, sex differences and estrous have different effects on fear conditioning, extinction and extinction retrieval.

کلیدواژه ها:

Extinction ، Fear memory ، mPFC ، Sex difference