HIT THE SNOOZE BUTTON: Researchers stimulate deeper sleep by optogenetically triggering certain patterns of brain activity in mice.© VALERIE LOISELEUX/ISTOCKPHOTO.COM
The paper A. Kim et al., “Optogenetically induced sleep spindle rhythms alter sleep architectures in mice,” PNAS, 109:20673-78, 2012. The finding Sleep spindles are EEG-detected oscillations in brain activity, lasting from 0.5 to 3 seconds, that occur during non-REM sleep. Earlier work had proposed that neurons generating sleep-spindle patterns might help maintain sleep, as studies tied increased sleep-spindle frequency to hypersomnia, or extended periods of sleep. But these were only correlations. Now, Hee-Sup Shin of the University of Science and Technology in Daejeon, Korea, and colleagues have shown for the first time that sleep spindles in fact are responsible for maintaining longer periods of non-REM sleep. The technique Shin’s group used optogenetics—a technique that activates selected neurons via a genetically inserted light receptor called channelrhodopsin2—to ...
