Central CRF and acute stress differentially modulate probabilistic reversal learning in male and female rats.

Autor: Bryce CA; Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2136 West Mall, Vancouver, BC, V6T 1Z4, Canada., Floresco SB; Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2136 West Mall, Vancouver, BC, V6T 1Z4, Canada. Electronic address: floresco@psych.ubc.ca.
Jazyk: angličtina
Zdroj: Behavioural brain research [Behav Brain Res] 2021 Jan 15; Vol. 397, pp. 112929. Date of Electronic Publication: 2020 Sep 28.
DOI: 10.1016/j.bbr.2020.112929
Abstrakt: Acute stress can have variable and sometimes sex-dependent effects on different executive functions, including cognitive flexibility, some of which may be mediated by increased corticotropin releasing factor (CRF). Previous studies on the effects of stress and CRF on cognitive flexibility have used procedures entailing deterministic rewards, yet how they may alter behavior when outcomes are probabilistic is unclear. The present study examined how acute stress and increased CRF activity alters probabilistic reversal learning (PRL) in male and female rats. Rats learned to discriminate between a 'correct' lever rewarded on 80 % of trials, and an "incorrect" lever delivering reward on 20 % of trials, with reward contingencies reversed after 8 consecutive correct choices. Separate groups received either intracerebroventricular infusions of CRF (3 μg) or restraint stress prior to a PRL session. Experiments examined how these manipulations affected learning when given prior to a one-day acquisition test or during performance in well-trained rats. Exogenous CRF, and to a lesser extent acute stress, impaired motivation across sexes, slowing deliberation times and increasing the number of trials omitted, particularly following a switch in reward contingencies. Neither manipulation significantly altered errors or reversal performance. However, increased CRF activity reduced negative feedback sensitivity. Across manipulations, females showed increased omissions and choice latencies, and were less sensitive to feedback than males. These results reveal the complexity with which stress, CRF, sex, and experience interact to alter aspects of motivation and probabilistic reinforcement learning and provide insight into how CRF activity may contribute to symptoms of stress-related disorders.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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