Department of Psychological Science, University of Vermont.
Behav Neurosci. 2024 Oct;138(5):366-381. doi: 10.1037/bne0000598. Epub 2024 May 16.
Pavlovian extinction reduces the performance of conditioned responses and occurs when the conditioned stimulus (CS) is repeatedly presented in the absence of the unconditioned stimulus (US). However, when the CS is experienced in a context that is different from the extinction context, there is a recovery of the conditioned response, a phenomenon known as renewal. There is some evidence that the renewal of appetitive conditioning is influenced by sex, with females failing to exhibit renewed responding. Further, there is recent evidence that renewal of fear might also not occur in female rats. In both appetitive and fear preparations, the lack of renewal in females has been postulated to be related to cycling ovarian hormones. Therefore, in Experiments 1 and 2, we directly compared fear renewal in males and females (Experiment 1) as well as ovariectomized (OVX) females (Experiment 2) when conditioning occurred in Context A, extinction in B, and testing in A (ABA renewal). Experiments 3 and 4 examined renewal when conditioning and extinction occurred in A and testing occurred in B (AAB renewal). In all experiments, renewal was not significantly different between male and female rats. Further, in Experiments 2 and 4, renewal did not differ between males, intact females, and OVX females. Additionally, in each experiment, there was no evidence that context excitation and/or inhibition contributed to renewal; instead suggesting that renewal was controlled by an occasion-setting mechanism. Overall, these results suggest little evidence for the role of sex in renewal of conditioned freezing and also indicate that cycling ovarian hormones have little role in the strength of renewal in female rats. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
巴甫洛夫式消退会降低条件反应的表现，当条件刺激 (CS) 在没有无条件刺激 (US) 的情况下反复呈现时就会发生。然而，当 CS 在与消退环境不同的环境中被体验时，条件反应会恢复，这种现象被称为更新。有一些证据表明，食欲条件反射的更新受到性别的影响，雌性动物无法表现出更新的反应。此外，最近有证据表明，雌性大鼠的恐惧更新也可能不会发生。在食欲和恐惧准备中，女性缺乏更新被认为与循环卵巢激素有关。因此，在实验 1 和 2 中，我们直接比较了雄性和雌性（实验 1）以及去卵巢（OVX）雌性（实验 2）的恐惧更新，当条件作用发生在环境 A 中，消退发生在环境 B 中，测试发生在环境 A 中（ABA 更新）。实验 3 和 4 检查了条件作用和消退发生在 A 中，测试发生在 B 中（AAB 更新）时的更新。在所有实验中，雄性和雌性大鼠之间的更新没有显著差异。此外，在实验 2 和 4 中，雄性、完整雌性和 OVX 雌性之间的更新没有差异。此外，在每个实验中，没有证据表明环境兴奋和/或抑制有助于更新；相反，这表明更新是由一种场合设定机制控制的。总体而言，这些结果表明，性别的作用在条件性冻结的更新中几乎没有证据，也表明循环卵巢激素在雌性大鼠更新的强度中作用不大。（PsycInfo 数据库记录（c）2024 APA，保留所有权利）。
