A consensus definition of cataplexy in mouse models of narcolepsy.
People with narcolepsy often have episodes of cataplexy, brief periods of muscle weakness triggered by strong emotions. Many researchers are now studying mouse models of narcolepsy, but definitions of cataplexy-like behavior in mice differ across labs. To establish a common language, the International Working Group on Rodent Models of Narcolepsy reviewed the literature on cataplexy in people with narcolepsy and in dog and mouse models of narcolepsy and then developed a consensus definition of murine cataplexy. The group concluded that murine cataplexy is an abrupt episode of nuchal atonia lasting at least 10 seconds. In addition, theta activity dominates the EEG during the episode, and video recordings document immobility. To distinguish a cataplexy episode from REM sleep after a brief awakening, at least 40 seconds of wakefulness must precede the episode. Bouts of cataplexy fitting this definition are common in mice with disrupted orexin/hypocretin signaling, but these events almost never occur in wild type mice. It remains unclear whether murine cataplexy is triggered by strong emotions or whether mice remain conscious during the episodes as in people with narcolepsy. This working definition provides helpful insights into murine cataplexy and should allow objective and accurate comparisons of cataplexy in future studies using mouse models of narcolepsy.
Scammell
Thomas E
TE
Department of Neurology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA. tscammel@bidmc.harvard.edu
Willie
Jon T
JT
Guilleminault
Christian
C
Siegel
Jerome M
JM
D000818:Animals; D002385:Cataplexy / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000502:physiology; D004195:Disease Models, Animal; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology; D007031:Hypothalamus / Q000503:physiopathology; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D051379:Mice; D009123:Muscle Hypotonia / Q000503:physiopathology; D009290:Narcolepsy / Q000503:physiopathology*; D009479:Neuropeptides / Q000502:physiology; D000068797:Orexins; D015398:Signal Transduction / Q000502:physiology
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins