In a novel study appearing this week in Neuron, Brandeis researchers identify for the first time a specific set of wake-promoting neurons in fruit flies that are analogous to cells in the much more complex sleep circuit in humans. The study demonstrates that in flies, as in mammals, the sleep circuit is intimately linked to the circadian clock and that the brain's strategies to govern sleep are evolutionarily ancient.
In the study, researchers quieted ventral lateral neurons (LNvs) and induced sleep in the flies by essentially altering the excitability of these cells with GABA, a major inhibitory neurotransmitter. GABA controls sleep onset and duration by opposing arousal. The same mechanism governs sleep in humans, explained Katherine Parisky, a post-doctoral researcher who coauthored the study led by Brandeis biologist Leslie Griffith's laboratory.
When it is time to wake up, the LNvs are believed to release a neuropeptide known as PDF, rousing the cells, and in turn, the flies. The cycle starts over again when GABA kicks in to quiet these neurons and give the flies a good night's sleep. The study found that mutant flies without PDF or its receptor were hypersomnolent.
The researchers' findings have implications for how sleep-promoting drugs are tested and developed. Currently, drugs that target GABA receptors are among the most widely-used sleep-promoting agents.
"Normally, to treat insomnia in humans, you use global drugs that suppress GABA throughout the brain," explained Griffith. "But it would be ideal to suppress only cells that are part of the sleep circuit."
Sleep problems, from insomnia to narcolepsy, affect millions of people and are extremely costly in both economic and human health terms. The next stage of research will involve researching how PDF controls wakefulness, said Parisky.
"We're taking apart the circuit bit by bit to see how it affects sleep," she said. "We already know that in humans, some people have problems falling asleep, while others can't stay asleep, and there are probably two different mechanisms for these behaviors in flies, as well," Parisky explained.
Fruit flies offer an excellent model organism in which to study sleep because their sleep circuit is relatively simple yet seemingly very similar to the sleep circuit in humans. A greater understanding of how the sleep circuit works in flies could help scientists to design and develop drugs that strategically target different sleep problems.
Laura Gardner | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences