Memory impairment induced by different types of prolonged stress is dependent on the phase of the estrous cycle in female rats.

Autor: do Nascimento EB; Health Science Center, Universidade Federal do Sul da Bahia, Teixeira de Freitas, BA, Brazil; Memory Studies Laboratory, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil., Dierschnabel AL; Memory Studies Laboratory, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil., de Macêdo Medeiros A; Laboratory of Behavioral Neuroscience, Department of Pharmacology, Universidade Federal de São Paulo, SP, Brazil., Suchecki D; Department of Psychobiology, Universidade Federal de São Paulo, SP, Brazil., Silva RH; Memory Studies Laboratory, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil., Ribeiro AM; Laboratory of Neuroscience and Bioprospecting of Natural Products, Department of Biosciences, Universidade Federal de São Paulo, Santos, SP, Brazil. Electronic address: alemrib@gmail.com.
Jazyk: angličtina
Zdroj: Hormones and behavior [Horm Behav] 2019 Sep; Vol. 115, pp. 104563. Date of Electronic Publication: 2019 Aug 09.
DOI: 10.1016/j.yhbeh.2019.104563
Abstrakt: A growing body of evidence demonstrates that estrogen and corticosterone (CORT) impact on cognition and emotion. On the one hand, ovarian hormones may have beneficial effects on several neurophysiological processes, including memory. On the other hand, chronic exposure to stressful conditions has negative effects on brain structures related to learning and memory. In the present study, we used the plus-maze discriminative avoidance task (PMDAT) to evaluate the influence of endogenous variations of sex hormones and exposure to different types of prolonged stressors on learning, memory, anxiety-like behavior and locomotion. Female Wistar rats were submitted to seven consecutive days of restraint stress (4 h/day), overcrowding (18 h/day) or social isolation (18 h/day) and tested in different phases of the estrous cycle. The main results showed that: (1) neither stress conditions nor estrous cycle modified PMDAT acquisition; (2) restraint stress and social isolation induced memory impairments; (3) this impairment was observed particularly in females in metestrus/diestrus; (4) stressed females in estrus displayed less risk assessment behavior, suggesting reduced anxiety-like behavior; (5) restraint stress and social isolation, but not overcrowding, elevated corticosterone levels. Taken together, our findings suggest that the phase of the estrous cycle is an important modulatory factor of the cognitive processing disrupted by stress in female rats. Negative effects were observed in metestrus/diestrus, indicating that the peak of sex hormones may protect females against stress-induced memory impairment.
(Copyright © 2019 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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