Concomitant loss of dynorphin, NARP, and orexin in narcolepsy
- 25 October 2005
- journal article
- Published by Ovid Technologies (Wolters Kluwer Health) in Neurology
- Vol. 65 (8), 1184-1188
- https://doi.org/10.1212/01.wnl.0000168173.71940.ab
Abstract
Background: Narcolepsy with cataplexy is associated with a loss of orexin/hypocretin. It is speculated that an autoimmune process kills the orexin-producing neurons, but these cells may survive yet fail to produce orexin. Objective: To examine whether other markers of the orexin neurons are lost in narcolepsy with cataplexy. Methods: We used immunohistochemistry and in situ hybridization to examine the expression of orexin, neuronal activity-regulated pentraxin (NARP), and prodynorphin in hypothalami from five control and two narcoleptic individuals. Results: In the control hypothalami, at least 80% of the orexin-producing neurons also contained prodynorphin mRNA and NARP. In the patients with narcolepsy, the number of cells producing these markers was reduced to about 5 to 10% of normal. Conclusions: Narcolepsy with cataplexy is likely caused by a loss of the orexin-producing neurons. In addition, loss of dynorphin and neuronal activity-regulated pentraxin may contribute to the symptoms of narcolepsy.Keywords
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