Comparative effects of the CRF agonist, ovine CRF, and CRF antagonist, astressin, on homecage behavior patterns and defense in the mouse Comparative effects of the CRF agonist, ovine CRF, and antagonist, astressin, on homecage behavior patterns and defense in the mouse

Date
2005
Authors
Farrokhi, Catherine F. Borna
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Journal Title
Journal ISSN
Volume Title
Publisher
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Corticotropin-releasing factor (CRF) has been implicated in physiological and behavioral responsivity to stress and emotions including fear and anxiety. Baseline CRF elevation has been linked to depression and anxiety disorders and its effects include disruptions in sleep patterns and feeding behaviors in animals. This study attempted to characterize the effects of CRF agonists and antagonists over time by evaluating the behavior patterns of CD-I mice in their homecage for a period of 3 hours following injection of the preferentially binding CRFI receptor agonist, ovine CRF, or the CRF receptor antagonist, astressin. Furthermore, anti-predator responses in a new pharmacologically validated anxiety model, the Rat Exposure Test (RET), were used to assess the defensive behaviors of mice following administration of these CRF compounds. Intracerebroventricular administration of ovine CRF interrupted sleep patterns over the 3 hour time period but also suppressed active behaviors including eating, drinking, grooming, rearing, and locomotor activity during the first hour of testing. Crouching or freezing was enhanced following both low and high doses of ovine CRF. Ovine CRF also produced an anxlOgemc response in the RET, decreasing locomotor activity and contact time while increasing freezing and avoidance behaviors. As expected, the CRF antagonist, astressin, did not disrupt behavior patterns in the homecage, since baseline anxiety levels were presumably low under this test condition. However, contrary to expectation, astressin also failed to produce an anxiolytic effect in the RET. This result provides a parallel to others which claim that the anxiolytic efficacy of astressin can only be observed following a pre-stress condition elevating CRF levels prior to infusion. Analysis combining ovine CRF followed by astressin may provide information on the efficacy of the latter in reducing elevated CRF levels. Further analysis of selective CRF1/CRF2 agonists and antagonists may reveal differential roles individual CRF receptor subtypes play in modulating defensive behaviors.
Description
Thesis (M.A.)--University of Hawaii at Manoa, 2005.
Includes bibliographical references (leaves 34-45).
52 leaves, bound ill. 29 cm
Keywords
Mice -- Behavior, Corticotropin releasing hormone -- Physiological effect, Corticotropin releasing hormone -- Agonists -- Physiological effect, Corticotropin releasing hormone -- Antagonists -- Physiological effect
Citation
Extent
Format
Geographic Location
Time Period
Related To
Theses for the degree of Master of Arts (University of Hawaii at Manoa). Psychology; no. 3201
Rights
All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.