Narcolepsy is a disabling sleep disorder that is characterized by persistent sleepiness, and cataplexy – an involuntary loss of waking muscle tone. Cataplexy and narcolepsy are caused by the loss of hypocretin containing neurons in the hypothalamus. However, it is hypothesized that dopamine is also involved in sleep and motor control and plays a role in cataplexy. This study investigated how manipulating dopamine affected sleep and cataplexy in narcoleptic mice devoid of hypocretin. We used d-amphetamine to increase endogenous dopamine levels and quinpirole (D2 agonist) to agonize D2 receptor sites. Amphetamine promoted wakefulness while decreasing sleep in wild-type mice, but was less effective in narcoleptic mice. Amphetamine also reduced cataplexy as well as sleep attacks (an indicator of sleepiness) in narcoleptic mice. Quinpirole had no effect on sleep or wakefulness; however, it potently increased cataplexy without affecting sleep attacks in narcoleptic mice.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/11171 |
| Date | 30 July 2008 |
| Creators | Tse, Gavin |
| Contributors | Peever, John H., Yeomans, John S. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 2976040 bytes, application/pdf |
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