Date of Award

Spring 2010

Document Type

Restricted Thesis

Terms of Use

© 2010 Helen Y. Hougen. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts

Department

Biology

First Advisor

Sara Hiebert Burch

Abstract

Previous studies have shown that laboratory mice (Mus musculus) in the cold increase their preference for diets supplemented with natural oils rich in PUFAs, but it is not known whether this phenomenon is driven by a change in preference for specific PUFAs. Arnold and Ruf (2008) proposed that increasing the n-6 to n-3 PUFA ratio in cardiac myocyte membranes decreases the risk of arrhythmia hibernators face and this study tests the hypothesis that normothermic mice in the cold increase their PUFA preference specifically to receive a similar benefit from n-6 PUFAs. Solutions of single fatty acids were used in a two-bottle paradigm to test the sensitivity, or relative level of detection, to and preference for an n-3 and an n-6 PUFA at 5°C and 23°C. To examine sensitivity for the two PUFAs, mice were offered either PUFA solutions of increasing concentrations (0% - 1%) simultaneously with a vehicle solution. Data suggest that they were more sensitive to both PUFAs at 5°C (P < 0.0001) compared with at 23°C but did not have a differential response to PUFA type (P = 0.48). When given both PUFAs simultaneously to determine preference, mice preferred n-6 to n-3 PUFAs (P < 0.0001) with no difference in preference between temperatures (P = 0.08). Together, the results of this study suggest that the increased PUFA preference in the cold is driven by an increased sensitivity to the PUFAs tested in this study but not a change in the relative preference for these PUFAs.

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