Despite its importance in everyday human function, very little is known about the regulation of sleep. In search of the underlying brain region responsible for sleep regulation, senior author Amita Sehgal, PhD, Professor of Neuroscience and a Howard Hughes Medical Institute (HHMI) Investigator, and colleagues turned their attention to the fruit fly.
"Fruit flies and humans share similar resting patterns," explains Sehgal. "Like humans, the sleeping states of fruit flies are characterized by periods of immobility over a twenty-four hour period, during which the fruit flies demonstrate reduced responsiveness to sensory stimuli."
By tinkering with the gene expression of multiple regions of the fruit fly brain, the research team was able to zero in on the adult mushroom body as the sleep center of the brain. They reported their findings in last week's issue of Nature.
To locate the brain region involved in sleep regulation, Sehgal manipulated the activity of an enzyme known as protein kinase A (PKA). Previous work in Sehgal's lab revealed that the higher the level of PKA activity, the lower the period of immobility, or sleep, in the fruit fly. By building upon this work, Sehgal and others set out to increase PKA activity in various regions of the brain and examine the subsequent sleeping patterns in the fruit flies. "Sleeping fruit flies" were defined as those that remained immobile for at least five minutes.
"From the beginning, we took the unbiased approach," explains Sehgal. "We targeted PKA activity to different areas of the fly brain to find out where PKA acts to
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Contact: Karen Kreeger
karen.kreeger@uphs.upenn.edu
215-349-5658
University of Pennsylvania School of Medicine
15-Jun-2006