( A Brandeis University study published t...)A resetting signal keeps circadian rhythm on track in Drosophila fruit flies

A Brandeis University study published this week in Nature shows for the first time that a molecular signal maintains coherence among brain clock cells that regulate daily activity of Drosophila melanogaster (fruit flies). The two key groups of neurons control morning and evening activity and are maintained in synch even when the flies are plunged into darkness for extended periods of time.

This daily resetting signal flows from the morning to the evening cells and maintains a 12-hour difference between the timing of morning and evening activity, without the need for any environmental cues. The Brandeis researchers came to this conclusion by speeding up only the morning cell clock or only the evening cell clock. The results showed clearly that these two clocks always remained coupled in a network that was governed by the morning cell signal.

"We think it very likely that something similar is occurring in the brain of mammals, including humans, because their clock neurons also maintain remarkable coherence," said Professor Michael Rosbash, director of the National Center for Behavioral Genomics at Brandeis, and a Howard Hughes Medical Institute investigator. "However, circadian brain anatomy in mammals is much more complicated and the tools much too primitive to allow a similar network approach at this time. Flies are state-of-the art. Fortunately, their circadian clocks and even neural mechanisms are quite conserved with mammals."

"We were curious about how these brain cells stay synchronized, so we controlled the way time was ticking in individual clocks: we made the morning cells run faster and the evening cells relatively slower, and the other way around," explained researcher Dan Stoleru. "In this fashion, we introduced phase differences between them. It turned out that no matter the manipulation, the morning cells set the pace of the entire system, so that the rhythm always stayed on track."

The study showed that the mornin
'"/>

Source:Brandeis University

Page: 1 2
Related biology news :

1. Travelers can avoid jet lag by resetting their body clocks
2. Plants respond similarly to signals from friends, enemies
3. Bound for destruction: Ubiquitination protects against improper Notch signaling
4. Viral protein influences key cell-signaling pathway
5. Researchers find promising cancer-fighting power of synthetic cell-signaling molecule
6. Edible bivalves as a source of human pathogens: signals between vibrios and the bivalve host.
7. Scientists discover that three overlapping signals in embryo help get the backbone right
8. After a time-shift, mixed signals from the circadian clock
9. Researchers make surprise discovery that some neurons can transmit three signals at once
10. Structure-building cell signals also may influence learning and memory
11. Fox Chase study shows that weakened T-cell receptor signals change T-cell lineage