Amygdala Lesions Reduce Cataplexy in Orexin Knock-Out Mice

• DOI: 10.1523/jneurosci.5632-12.2013
• Publication Date: 2013-06-05T16:40:55Z
• Authors: C. R. Burgess; Y. Oishi; T. Mochizuki; J. H. Peever; T. E. Scammell
• Keywords: Dorsal raphe nucleus; Locus coeruleus; Tegmentum

Narcolepsy is characterized by excessive sleepiness and cataplexy, sudden episodes of muscle weakness during waking that are thought to be an intrusion rapid eye movement sleep atonia into wakefulness. One the most striking aspects cataplexy it often triggered strong, generally positive emotions, but little known about neural pathways through which emotions trigger atonia. We hypothesized amygdala functionally important for because has a role in processing emotional stimuli contains neurons active cataplexy. Using anterograde retrograde tracing mice, we found GABAergic central nucleus heavily innervate maintain tone such as those ventrolateral periaqueductal gray, lateral pontine tegmentum, locus ceruleus, dorsal raphe. then bilateral, excitotoxic lesions markedly reduced orexin knock-out model narcolepsy. These did not alter basic sleep–wake behavior substantially triggering Lesions also events conditions associated with high arousal (i.e., wheel running chocolate). observations demonstrate part circuitry underlying suggest increased activity response could directly inhibiting brainstem regions suppress