Amygdala kindling is commonly used to study the mechanisms involved in epileptogenesis, with long-term amygdala kindling providing a useful model of the behavioural disturbances such as heightened anxiety that can occur between epileptic seizures. The purpose of this thesis was to determine whether increased fear behaviours exhibited by long-term amygdala kindled rats are reflective of previously observed kindling-mediated alterations in the hippocampus. As the hippocampus plays an integral role in contextual learning, the ability of the animals to habituate to a novel environment was evaluated, in order to determine if the rats displayed impairments in this hippocampal-dependent function. In Experiment 1, long-term kindled rats demonstrated consistently elevated exploration and fear over repeated exposure to an initially novel open field, indicating impaired habituation. In Experiment 2, all kindled rats showed elevated exploration and an inability to form a home base in relation to static visual cues, again demonstrating an inability to habituate over repeated exposures to the initially novel environment. Rats that had received 30 or 60 stimulations demonstrated hyperexploratory behaviour and elevated fear, although this behaviour did dissipate to a certain degree by the final day of testing. Long-term kindled rats, having received 99 stimulations, demonstrated extremely heightened fear behaviours that interfered with normal exploration, home base formation and habituation. These fear behaviours included high levels of freezing, disorganized running, and purposive jumping from the open field. Taken together, these results indicate that long-term amygdala kindling does produce deficits in habituation to an initially novel environment. As habituation necessarily involves the hippocampal-dependent roles of contextual learning and memory, the current research suggests that long-term kindling does impair hippocampal function and that this may contribute to kindling-induced fear behaviours. This research may help to understand the mechanisms involved in emotional disturbances experienced by human epileptics.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-09142007-085640 |
| Date | 14 September 2007 |
| Creators | Andersen, Devon Rose |
| Contributors | Mulligan, Sean, Kelly, Debbie M., Kalynchuk, Lisa E., Crossley, Margaret |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-09142007-085640/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0071 seconds