Department of Psychological and Brain Sciences and Institute for Neuroscience, Texas A&M University, College Station, Texas, United States of America.
PLoS One. 2022 Jun 10;17(6):e0264797. doi: 10.1371/journal.pone.0264797. eCollection 2022.
Extinction learning is central to exposure-based behavioral therapies for reducing fear and anxiety in humans. However, patients with fear and anxiety disorders are often resistant to extinction. Moreover, trauma and stress-related disorders are highly prone to relapse and are twice as likely to occur in females compared to males, suggesting that females may be more susceptible to extinction deficits and fear relapse phenomena. In this report, we tested this hypothesis by examining sex differences in a stress-induced extinction learning impairment, the immediate extinction deficit (IED), and renewal, a common form of fear relapse. In contrast to our hypothesis, there were no sex differences in the magnitude of the immediate extinction deficit in two different rat strains (Long-Evans and Wistar). However, we did observe a sex difference in the renewal of fear when the extinguished conditioned stimulus was presented outside the extinction context. Male Wistar rats exhibited significantly greater renewal than female rats, a sex difference that has previously been reported after appetitive extinction. Collectively, these data reveal that stress-induced extinction impairments are similar in male and female rats, though the context-dependence of extinction is more pronounced in males.
灭绝学习是暴露疗法治疗人类恐惧和焦虑的核心。然而，患有恐惧和焦虑障碍的患者通常对灭绝有抵抗力。此外，创伤和应激相关障碍极易复发，女性的复发几率是男性的两倍，这表明女性可能更容易出现灭绝缺陷和恐惧复发现象。在本报告中，我们通过检查应激诱导的灭绝学习障碍、即刻灭绝缺陷（IED）和更新（恐惧复发的常见形式）中的性别差异来检验这一假设。与我们的假设相反，在两个不同的大鼠品系（Long-Evans 和 Wistar）中，即刻灭绝缺陷的程度没有性别差异。然而，当被灭绝的条件刺激在灭绝环境之外呈现时，我们确实观察到了恐惧更新的性别差异。雄性 Wistar 大鼠表现出的恐惧更新明显大于雌性大鼠，这一性别差异之前在奖励性灭绝后也有报道。总的来说，这些数据表明，应激诱导的灭绝损伤在雄性和雌性大鼠中相似，尽管灭绝的上下文依赖性在雄性中更为明显。
