Examining the Effects of Individually Ventilated Cages on Rat Defensive Behaviour
Loading...
Authors
Streatch, Benjamin
Date
Type
thesis
Language
eng
Keyword
Defensive Behaviours , Social Buffering , Animal Models of Anxiety , Individually Ventilated Cage , Social Isolation
Alternative Title
Abstract
Historically, laboratory rodents were housed in conventional open-topped cages (OTCs), which are held under ambient ventilation and the intracage environment is directly influenced by the environment of the colony room. Many research facilities now replace these OTCs with individually ventilated cages (IVCs), which are hermetically sealed chambers designed to protect both laboratory rodents and experimenters. Evidence suggests IVCs may increase rodent defensive behaviours, potentially because their hermetic seal prevents the flow of olfactory and auditory information between cages. While social housing is well-known to buffer rodent stress, it is unclear if these protective effects will endure in an IVC system. I hypothesized that IVCs would increase defensive behaviour relative to OTCs. I further hypothesized that single-housed rats would be more behaviourally defensive compared to pair-housed rats due to the protective effects of social buffering, but only in the OTC condition. Forty-eight male rats were randomly assigned to OTC or IVC housing, either singly or in same-sex pairs. After four weeks of acclimating, all rats underwent testing in the Elevated Plus-Maze (EPM) and the Shock-Probe Burying Test (SPBT), followed by the removal and weighing of the adrenal glands. There was evidence of social buffering in the EPM, as single-housed rats had lower levels of open arm activity than pair-housed rats, suggesting more behavioural defensiveness. Further, pair-housed rats maintained in OTCs completed fewer protected stretch attend postures than pair-housed rats in IVCs, suggesting lower levels of behavioural defensiveness in response to a potential threat. In the SPBT, there were no differences in defensive burying between any experimental conditions. However, there was further evidence of social buffering as singly housed rats averaged significantly fewer stretch attend postures than pair-housed rats, suggesting an increase in anxiety-like behaviour in response to a localizable threat. Surprisingly, these behavioural effects were not supported with physiological data, as there were no effects of cage type or housing on adrenal gland weight. Overall, these findings provide evidence that IVCs influence rats’ defensive behaviours, that social buffering does have protective effects in IVCs, and that further research is needed to determine how IVCs impact animal behaviour and welfare.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
Attribution 3.0 United States
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
Attribution 3.0 United States