The role of corticotropin-releasing and acute stress in modulating cognitive flexibility and decision making : physiological and behavioural interactions with mesolimbic dopamine
department or school: Arts, Faculty of
department or school: Psychology, Department of
data provider: DSpace
degree campus: UBCV
creator: Bryce, Courtney Aryn
issued: 2020-03-05T23:40:57Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The stress response is a co-ordinated reaction to real or perceived threats. One arm of the response is the hypothalamic-pituitary-adrenal axis, initiated by corticotropin-releasing factor (CRF). Centrally-active CRF mediates many of the rapid behavioural stress responses. Indeed, CRF mediates, and exogeneous CRF mimics, the acute stress-induced bias away from more valuable rewards requiring greater effort. In Chapter 1, we discuss relevant research comparing acute stress and central CRF infusion at the circuit level and as it relates to different cognitive domains. In Chapters 2 and 3, we examine how acute stress and increased central CRF activity alter cognitive flexibility in both sexes, and risk/reward decision making in males. Using a probabilistic reversal learning (PRL) task, results suggested that acute stress impaired PRL in males, but CRF slightly facilitated flexibility across both sexes, with minimal overall sex differences. Using two decision making tasks, we found that acute stress increased reward sensitivity and CRF impaired optimal risky choice with external cues, whereas neither manipulation altered risky choice when reward contingencies were internally generated. Moreover, CRF markedly reduced motivation in all tasks. When viewed together, we found that CRF hyperactivity altered behaviour in a manner more similar to chronic than acute stress manipulations. In search of potential mechanisms, we probe the role of centrally-active CRF in altering ventral tegmental area dopamine neuron activity in Chapter 4, revealing that CRF increased dopamine neuron population activity. Chapter 5 examines the role of increased mesolimbic dopamine signaling on effort-related decision making. Here, we found increased nucleus accumbens (NAc) D2 receptor activity biased choice away from the more valuable, but more physically onerous, reward in a manner parallel to central CRF treatment. Collectively, these latter results suggest that increased CRF signaling enhances to…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/73685
note: THE ROLE OF CORTICOTROPIN-RELEASING FACTOR AND ACUTE STRESS IN MODULATING COGNITIVE FLEXIBILITY AND DECISION MAKING: PHYSIOLOGICAL AND BEHAVIOURAL INTERACTIONS WITH MESOLIMBIC DOPAMINE by Courtney Aryn Bryce B.A. (High Honours), The University of Saskatchewan, 2013 M.A., The University of British Columbia, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Psychology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) March 2020 © Courtney Aryn Bryce, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: The role of corticotropin-releasing factor and acute stress in modulating cognitive flexibility and decision making: physiological and behavioural interactions with mesolimbic dopamine submitted by Courtney Bryce in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology Examining Committee: Stan Floresco, Psychology Supervisor Joanne Weinberg, Cellular and Physiological Sciences Supervisory Committee Member Frances Chen, Psychology Supervisory Committee Member Liisa Galea, Psychology University Examiner Victor Viau, Cellular and Physiological Sciences University Examiner Additional Supervisory Committee Members: John Mantsch, External Examiner, Biomedical Sciences Supervisory Committee Member Ujendra Kumar, Chair, Pharmaceutical Sciences Supervisory Committee Member iii Abstract The stress response is a co-ordinated reaction to real or perceived threats. One arm of the response is the hypothalamic-pituitary-adrenal axis, initiated by corticotropin-releasing factor (CRF). Centrally-active CRF mediates many of the rapid behavioural stress responses. Indeed, CRF mediates, and exogeneous CRF mimics, the acute stress-induced bias away from more valuable rewards requiring greater effort. In Chapter 1, we discuss rele…
has type: Thesis/Dissertation
date issued: 2020-05
is shown at: 10.14288/1.0388869
language: eng
degree discipline: Psychology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/73685