Insomniac fish shed light on the molecular basis of sleep disorders

October 15, 2007

Sleep disorders are common and poorly understood. In humans, narcolepsy is a sleep disorder associated with sleepiness, abnormal dreaming, paralysis and insomnia. Neuropeptides called hypocretins are implicated in this disorder. A new study by Yokogawa and colleagues at Stanford University now reveals that fish, like mammals, sleep, and their hypocretin receptor plays an important role. Their work is published online this week in the open-access journal PLoS Biology.

The authors first generated a mutant fish in which the hypocretin system was disrupted. Intriguingly, this first fish sleep mutant did not display sleepiness or paralysis but showed a 30% reduction of its sleep time at night and a 60% decrease in sleep bout length compared with non-mutant fish. They also studied the relationships between the hypocretin system and other sleep regulatory brain systems in zebrafish and found differences in expression patterns in the brain that may explain the differences in behavioral effects. Their study illustrates how a sleep regulatory system may have evolved across vertebrate phylogeny. Zebrafish, a powerful genetic model that has the advantage of transparency to study neuronal networks in vivo, can be used to study sleep.
-end-
Citation: Yokogawa T, Marin W, Faraco J, Pe´zeron G, Appelbaum L, et al. (2007) Characterization of sleep in zebrafish and insomnia in hypocretin receptor mutants. PLoS Biol 5(10): e277. doi:10.1371/journal.pbio.0050277

CONTACT:
Emmanuel Mignot
Howard Hughes Medical Institute, Stanford University
Center for Narcolepsy
Stanford, CA 94304
650-725-6517
650-725-4913 (fax)
mignot@stanford.edu

PLEASE MENTION THE OPEN-ACCESS JOURNAL PLoS BIOLOGY (www.plosbiology.org) AS THE SOURCE FOR THESE ARTICLES AND PROVIDE A LINK TO THE FREELY-AVAILABLE TEXT. THANK YOU.

PDF: http://www.plos.org/press/plbi-05-10-mignot.pdf

All works published in PLoS Biology are open access. Everything is immediately available--to read, download, redistribute, include in databases, and otherwise use--without cost to anyone, anywhere, subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

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