Timing Sleep And Wakefulness

Johanna Meijer and colleagues monitored the vigilance state of rats by recording their brain (EEG) and muscle (EMG) signals. At the same time, the experimenters recorded neuronal activity within a brain region called the suprachiasmatic nucleus (SCN) to monitor the output of the circadian clock. Driven by cycles of gene transcription and translation, activity in the SCN normally oscillates with day and night cycles. They found a clear correlation between vigilance states and activity in the SCN. Furthermore, by using sleep deprivation experiments, they tested for a casual relationship. Indeed, during sleep deprivation, neuronal activity in the SCN failed to show expected changes in electrical activity for the time of day, demonstrating that activity in the SCN is determined not only by the molecular machinery of the circadian clock, but also by sleep need. A next step will be to determine how changes in need for sleep are communicated to the SCN at the molecular level.

Author contact:

Johanna Meijer
University of Leiden, The Netherlands
Tel: +31 71 527 67 15
E-mail: J.H.Meijer@lumc.nl

Additional contact for comment on paper:

Christopher Colwell
University of California at Los Angeles, Los Angeles, CA, USA.
Tel: +1 310 206 3973
E-mail: ccolwell@mednet.ucla.edu

Article available online.

(C) Nature Neuroscience press release.

Message posted by: Trevor M. D'Souza