title: Glucocorticoid-induced impairment of long-term memory retrieval in female rats: influences of estrous cycle and estrogen.
abstract: Using an inhibitory avoidance (IA) task, the effects of glucocorticoids on memory retrieval in intact and ovariectomized (OVX) female rats were investigated. Young adult female rats were trained in a one trial IA task (1-mA, 3-s footshock). The latency to reenter the dark compartment of the apparatus was recorded in the retention test performed 48h after training. Pre-retrieval injection of corticosterone (CORT, 1, 3, and 10mg/kg) to OVX rats impaired memory retrieval at all doses tested. Similar administration of CORT (3mg/kg) in intact female rats impaired memory retrieval in the estrus phase (when endogenous plasma levels of estrogen are low) but not in the proestrus phase (when endogenous levels of estrogen are high). Concurrent administration of CORT (3mg/kg) and 17-β-estradiol (15μg/kg) in both proestrus and estrous phases impaired memory retrieval. Our findings indicate that the effects of corticosterone on memory retrieval are modulated by the estrous cycle and 17-β-estradiol.
authors.affiliation: Department of Biology, Faculty of Science, Arak University, Arak 38156-8-8349, Iran; Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Raziyeh
authors.initials: R
authors.lastname: Mohammadkhani
authors.affiliation: Department of Biology, Faculty of Science, Arak University, Arak 38156-8-8349, Iran.
authors.forename: Niloufar
authors.initials: N
authors.lastname: Darbandi
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Vafaei
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran; Student's Research Committee, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Ahmadalipour
authors.affiliation: Laboratory of Learning and Memory, Research Center and Department of Physiology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran. Electronic address: Rashidy-pour@semums.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Rashidy-Pour
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D003345:Corticosterone / Q000494:pharmacology / Q000502:physiology*; D004597:Electroshock; D004958:Estradiol / Q000494:pharmacology / Q000502:physiology*; D030762:Estrous Cycle / Q000187:drug effects; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology / Q000502:physiology*; D057567:Memory, Long-Term / Q000187:drug effects / Q000502:physiology*; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology*; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005938:Glucocorticoids; D004958:Estradiol; D003345:Corticosterone
keywords: Corticosterone; Estrous cycle; Inhibitory avoidance task; Memory retrieval