Ball Kevin T, Best Olivia, Hagan Erin, Pressimone Claire, Tosh Lindsay
Department of Psychology, Bloomsburg University of Pennsylvania, 400 E. 2nd St., Bloomsburg, PA 17815, USA.
Department of Psychology, Bloomsburg University of Pennsylvania, 400 E. 2nd St., Bloomsburg, PA 17815, USA.
Physiol Behav. 2020 Jul 1;221:112900. doi: 10.1016/j.physbeh.2020.112900. Epub 2020 Apr 4.
Previous research in our lab has established a causal role for chronic stress exposure in subsequent increases in relapse-like behaviors in male rats with a history of palatable food self-administration. Given that many of the neurobehavioral consequences of stress are sex dependent, we aimed to determine whether sex differences exist with regard to the effects of chronic stress on relapse. Additionally, because high trait anxiety confers vulnerability to stress-related disorders, we examined whether individual differences in trait anxiety were related to differences in relapse-like behavior after chronic stress exposure. Following elevated plus maze testing for classification into high- or low-anxiety phenotypes, male and female rats responded for highly palatable food pellets. During subsequent extinction training, stress was manipulated (0 or 90 min restraint/day for 7 days). Rats were then tested for cue- and pellet priming-induced reinstatement of palatable food seeking. Results showed that female rats displayed higher levels of responding during cue-induced reinstatement tests compared to males, and that a history of chronic stress caused an attenuation of cue-induced reinstatement in female, but not male, rats. Regarding pellet priming-induced reinstatement, there was a three-way interaction such that neither stress history nor anxiety phenotype was related to reinstatement in females, but a history of stress in males caused increased and decreased responding in low- and high-anxiety rats, respectively. These results suggest that biological sex and trait anxiety level may help to explain differences in vulnerability to relapse among individuals exposed to chronic stress. Such information may be useful in designing more personalized and effective treatments for obesity and eating disorders.
我们实验室之前的研究已经确定，对于有美味食物自我给药史的雄性大鼠，慢性应激暴露在随后复发样行为增加中起因果作用。鉴于应激的许多神经行为后果存在性别差异，我们旨在确定慢性应激对复发的影响是否存在性别差异。此外，由于高特质焦虑使人易患与应激相关的疾病，我们研究了特质焦虑的个体差异是否与慢性应激暴露后复发样行为的差异有关。在通过高架加迷宫测试将大鼠分为高焦虑或低焦虑表型后，雄性和雌性大鼠对高度美味的食物颗粒做出反应。在随后的消退训练期间，对应激进行了操控（每天约束90分钟，持续7天）。然后对大鼠进行线索和食物颗粒启动诱导的美味食物寻求恢复测试。结果表明，与雄性相比，雌性大鼠在线索诱导的恢复测试中表现出更高水平的反应，并且慢性应激史导致雌性大鼠而非雄性大鼠的线索诱导恢复减弱。关于食物颗粒启动诱导的恢复，存在三因素交互作用，即应激史和焦虑表型均与雌性大鼠的恢复无关，但雄性大鼠的应激史分别导致低焦虑和高焦虑大鼠的反应增加和减少。这些结果表明，生物性别和特质焦虑水平可能有助于解释暴露于慢性应激的个体在复发易感性方面的差异。这些信息可能有助于设计更个性化、更有效的肥胖症和饮食失调治疗方案。
