Researchers uncover new ways sleep-wake patterns are like clockwork

May 23, 2012

Researchers at New York University and Albert Einstein College of Medicine of Yeshiva University have discovered new ways neurons work together to ease the transition between sleep and wakefulness. Their findings, which appear in the journal Neuron, provide additional insights into sleep-wake patterns and offer methods to explore what may disrupt them.

Their study explored the biological, or circadian, clocks of Drosophila fruit flies, which are commonly used for research in this area. This is because it is relatively easy to find with malfunctioning biological clocks and then to identify the genes underlying the altered behavior. Such studies in have allowed the identification of similar "" in , which function in largely the same manner as they do in a fly's clock.

In the Neuron study, the researchers moved up a level to study how pacemaker clock neurons—which express clock genes—interact with each other. Specifically, they looked at the relationship between master pacemaker neurons, which control the overall pace of the circadian system, and non-master pacemaker neurons, whose role in circadian rhythms has been less clear.

To do so, they examined flies with normally functioning master and non-master clock neurons and compared them with mutant flies in which the signaling of these neurons was either increased or decreased. These comparisons allowed the researchers to isolate the individual roles of these neurons and, in particular, to understand how master and non-master pacemaker neurons work together to control circadian rhythms.

Their results revealed a previously unknown role for non-master pacemaker neurons. Specifically, these neurons employ a neurotransmitter, glutamate, which suppresses signaling of the master pacemaker neurons during the evening. Artificially increasing this suppression by the non-master clock neurons in the morning made it much harder for flies to wake up. So in normal flies, these non-master pacemaker neurons have to stand aside at dawn, allowing the master neurons to fire to wake up the fly. The authors concluded that the balance between signaling of these two groups of clock neurons helps to set the precise time of the transition between and wakefulness.

"Our work shifts the emphasis away from clock genes and starts to address how clock neurons function in a neural network to regulate behavior," explained Justin Blau, an associate professor in NYU's Department of Biology and one of the study's co-authors. "And it shows the importance of studying individual groups of clock , since different subsets can have opposite effects on animal behavior."

"This work helps to elucidate the neurotransmitters and receptors that facilitate communication between specific groups of nerve cells that regulate circadian rhythm," said co-author Myles Akabas, professor of Physiology & Biophysics and of Neuroscience at Albert Einstein College of Medicine. "It demonstrates the power of collaborative interdisciplinary research to address the molecular and cellular basis for behavior."

Explore further: Rising star of brain found to regulate circadian rhythms

Related Stories

Rising star of brain found to regulate circadian rhythms

April 14, 2011
The circadian system that controls normal sleep patterns is regulated by a group of glial brain cells called astrocytes, according to a study published online on April 14th in Current Biology, a Cell Press publication. Neuroscientists ...

Molecular path from internal clock to cells controlling rest and activity revealed in new study

February 7, 2012
(PhysOrg.com) -- The molecular pathway that carries time-of-day signals from the body's internal clock to ultimately guide daily behavior is like a black box, says Amita Sehgal, PhD, the John Herr Musser Professor of Neuroscience ...

Recommended for you

Researchers create tool to measure, control protein aggregation

October 22, 2017
A common thread ties seemingly unlinked disorders like Alzheimer's disease and type II diabetes together. This thread is known as protein aggregation and happens when proteins clump together. These complexes are a hallmark ...

Want to control your dreams? Here's how

October 19, 2017
New research at the University of Adelaide has found that a specific combination of techniques will increase people's chances of having lucid dreams, in which the dreamer is aware they're dreaming while it's still happening ...

Researchers find shifting relationship between flexibility, modularity in the brain

October 19, 2017
A new study by Rice University researchers takes a step toward what they see as key to the advance of neuroscience: a better understanding of the relationship between the brain's flexibility and its modularity.

Brain training can improve our understanding of speech in noisy places

October 19, 2017
For many people with hearing challenges, trying to follow a conversation in a crowded restaurant or other noisy venue is a major struggle, even with hearing aids. Now researchers reporting in Current Biology on October 19th ...

Investigating the most common genetic contributor to Parkinson's disease

October 19, 2017
LRRK2 gene mutations are the most common genetic cause of Parkinson's disease (PD), but the normal physiological role of this gene in the brain remains unclear. In a paper published in Neuron, Brigham and Women's Hospital ...

New procedure enables cultivation of human brain sections in the petri dish

October 19, 2017
Researchers at the University of Tübingen have become the first to keep human brain tissue alive outside the body for several weeks. The researchers, headed by Dr. Niklas Schwarz, Dr. Henner Koch and Dr. Thomas Wuttke at ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.