Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dementia induced and blocked in Parkinson's fly model

04.08.2009
Parkinson's disease is well-known for impairing movement and causing tremors, but many patients also develop other serious problems, including sleep disturbances and significant losses in cognitive function known as dementia.

Now researchers at Washington University School of Medicine in St. Louis have modeled Parkinson's-associated dementia for the first time. Scientists showed that a single night of sleep loss in genetically altered fruit flies caused long-lasting disruptions in the flies' cognitive abilities comparable to aspects of Parkinson's-associated dementia. They then blocked this effect by feeding the flies large doses of the spice curcumin.

"Clinical trials of curcumin to reduce risk of Parkinson's disease are a future possibility, but for now we are using the flies to learn how curcumin works," says author James Galvin, M.D., a Washington University associate professor of neurology who treats patients at Barnes-Jewish Hospital. "This should help us find other compounds that can mimic curcumin's protective effects but are more specific."

Galvin and senior author Paul Shaw, Ph.D., assistant professor of neurobiology, publish their results in the journal Sleep on Aug. 1.

Galvin is an expert in cognitive impairments in human Parkinson's disease; Shaw studies sleep and the brain in fruit flies. The researchers decided collaborate based in part on evidence that increased sleep loss in Parkinson's patients can precede or coincide with increased severity in other Parkinsonian symptoms.

More than 74 percent of Parkinson's patients have trouble sleeping, and up to 80 percent of patients 65 and older who have Parkinson's disease for seven years will develop dementia, according to Galvin.

Shaw's lab has linked sleep loss to changes in the dopaminergic system of the brain, the part of the brain that produces the neurotransmitter dopamine and is at the center of the damage caused by Parkinson's.

"In healthy flies, sleep deprivation decreases dopamine receptor production and causes temporary learning impairments that are fully restored after a two-hour nap," Shaw says.

Shaw and Galvin studied fruit flies genetically modified to make a human protein called alpha-synuclein in their brains. Scientists don't yet know what alpha-synuclein does, nor have they found a fly counterpart for it. But they have shown that it aggregates in the brains of Parkinson's disease patients and believe the processes that cause the aggregations are harming dopamine-producing cells.

Prior studies of fruit flies with human alpha-synuclein in their brains showed that the flies, like human Parkinson's patients, also lose dopamine-producing neurons, have movement-related problems and develop alpha-synuclein aggregations. But scientists had yet to evaluate the flies for signs of dementia.

Lead author Laurent Seugnet, Ph.D., research associate at L'Ecole Supérieure de Physique Chimie Industrielles in France, first tested the flies' learning ability using a procedure he helped develop in Shaw's lab. For the test, Seugnet placed flies in a vial with two branches: one lighted branch containing quinine, a bitter-tasting substance flies prefer to avoid; and a darkened but quinine-free branch. After a few trials, normal flies learn to suppress their natural attraction to the light and fly into the darkened vial instead to avoid the quinine.

Flies with alpha-synuclein in their brains could still learn when they were middle-aged, or about 16 to 20 days old. But when Seugnet deprived them of sleep for 12 hours, he found that their ability to remember was more severely impaired than that of young healthy flies that had also been sleep-deprived.

"This was still true even 10 days later, so it seemed to be a lasting effect," says Seugnet.

Galvin had earlier found that curcumin, a derivative of the spice turmeric, blocks alpha-synuclein aggregation in cell models of Parkinson's disease. Based on this, Seugnet fed curcumin to a new batch of flies, repeated the tests and found middle-aged flies with alpha-synuclein retained their ability to learn as well as normal young flies.

"Thanks to this model our labs have created, Dr. Galvin and I can not only quickly test potential new treatments for these symptoms of Parkinson's, we can also move up our treatments in terms of the timeline along which the disorder develops," says Shaw. "That may give us a real chance to change the course of the disease."

Seugnet L, Galvin JE, Suzuki Y, Gottschalk L, Shaw PJ. Persistent short-term memory defects following sleep deprivation in a Drosophila model of Parkinson disease. Sleep, Aug. 1, 2009

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Michael C. Purdy | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>