title: Post-training corticosterone inhibits the return of fear evoked by platform stress and a subthreshold conditioning procedure in Sprague-Dawley rats.
abstract: The return of fear is an important issue in anxiety disorder research. Each time a fear memory is reactivated, it may further strengthen overactivation of the fear circuit, which may contribute to long-term maintenance of the fear memory. Recent evidence indicates that glucocorticoids may help attenuate pathological fear, but its role in the return of fear is unclear. In the present study, systemic corticosterone (CORT; 25mg/kg) administration 1h after fear conditioning did not impair the consolidation process but significantly suppressed the return of fear evoked by a subthreshold conditioning (SC) procedure and elevated platform (EP) stress. Compared with the SC-induced return of fear, acute stress-induced return was state-dependent. In addition, post-training CORT treatment increased the adrenocorticotropic response after EP stress, which indicates that the drug-induced suppression of the return of fear may possibly derive from its regulation effect of the hypothalamic-pituitary-adrenal axis reactivity to stress. These results suggest that post-training CORT administration may help inhibit the return of fear evoked by EP or SC stress. The possible mechanisms involved in the high-dose CORT-induced suppression of the SC- and EP-induced return of fear are discussed.
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China; School of Education Science, Henan University, Kaifeng 475001, Henan Province, PR China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Xing
authors.affiliation: School of Education Science, Henan University, Kaifeng 475001, Henan Province, PR China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Yunjing
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Zhengkui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, PR China. Electronic address: zhengxg@psych.ac.cn.
authors.forename: Xigeng
authors.initials: X
authors.lastname: Zheng
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects*; D003345:Corticosterone / Q000097:blood / Q000494:pharmacology*; D005108:Extinction, Psychological / Q000187:drug effects; D005239:Fear / Q000187:drug effects*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000523:psychology*
chemical_list: D000324:Adrenocorticotropic Hormone; D003345:Corticosterone
keywords: Corticosterone; Extinction; Fear conditioning; Fear return; Subthreshold conditioning procedure