Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mouse model of Parkinson's reproduces nonmotor symptoms

25.06.2009
The classic symptoms of Parkinson's disease involve tremor, stiffness and slow movements. Over the last decade, neurologists have been paying greater attention to non-motor symptoms, such as digestive and sleep problems, loss of sense of smell and depression.

A genetically engineered mouse reproduces many of the non-motor symptoms associated with Parkinson's disease seen in humans and sheds light on their possible causes, Emory scientists report in the June 24 issue of the Journal of Neuroscience.

"These mice are very useful for studying the major non-motor symptoms of Parkinson's because they have them together as a package," says Gary Miller, PhD, professor of environmental and occupational health in the Rollins School of Public Health and neurology and pharmacology in the School of Medicine at Emory University.

The mice were engineered to be deficient in VMAT2 (vesicular monoamine transporter 2), a protein that helps to store the brain chemicals Parkinson's patients gradually lose the ability to produce.

Miller and his colleagues previously published a description of the neurodegeneration of the VMAT2-deficient mice, but focusing on the part of the brain associated with Parkinson's motor symptoms. Graduate student Tonya Taylor is first author of the 2009 paper on non-motor symptoms.

The VMAT2-deficient mice could become research tools in the search for medications to treat non-motor symptoms, Miller says. Most non-motor symptoms do not respond to L-dopa, the medication most commonly given to people with Parkinson's, he notes.

L-dopa can be converted by the body into the neurotransmitter dopamine, the lack of which is responsible for the main motor difficulties in Parkinson's.

Within brain cells, VMAT2 packages neurotransmitters such as dopamine, norepinephrine, and serotonin into vesicles, containers that deliver chemical messages to other cells. In the VMAT2-deficient mice, the improperly stored neurotransmitters are thought to damage brain cells.

In other mouse models of Parkinson's, scientists use chemicals such as the pesticide rotenone or the neurotoxin MPTP to kill the brain cells analogous to those that patients gradually lose, or they have the mice overproduce proteins that aggregate into toxic clumps.

The VMAT2-deficient mice have aggregated proteins in their brains, which appears to be a byproduct of improper neurotransmitter storage, Miller says.

The Emory scientists showed that the mice have delayed emptying of the stomach, they fall asleep more quickly and they have a loss of the sense of smell.

In tests scientists use to model depression, aged VMAT2-deficient mice display signs of depression and respond to classical antidepressants. They also showed greater reluctance to explore elevated, lighted places, a measure of anxiety.

The mice have normal vision, sense of touch and muscle strength, qualities Miller says are important to show that the mice are not generally sick – a difference from some toxin models.

The research was supported by the Emory Parkinson's Research Collaborative Environmental Research Center funded by the National Institute of Environmental Health Sciences.

Other investigators involved in the research include Tonya Taylor, Mike Caudle, Kennie Shepherd, Alireza Noorian, Chad Jackson, Mike Iuvone, David Weinshenker, and James Greene.

Reference:

Non-motor symptoms of Parkinson's disease revealed in an animal model with reduced monoamine storage capacity. T. Taylor, W. Caudle, K. Shepherd, A. Noorian, C. Jackson, P.M. Iuvone, D. Weinshenker, J. Greene, and G. Miller. J. Neurosci. 29, xx-yy (2009).

The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service. Its components include the Emory University School of Medicine, Nell Hodgson Woodruff School of Nursing, and Rollins School of Public Health; Yerkes National Primate Research Center; Emory Winship Cancer Institute; and Emory Healthcare, the largest, most comprehensive health system in Georgia. Emory Healthcare includes: The Emory Clinic, Emory-Children's Center, Emory University Hospital, Emory University Hospital Midtown, Wesley Woods Center, Emory University Orthopaedics & Spine Hospital, the jointly owned Emory-Adventist Hospital, and EHCA, a limited liability company created with Hospital Corporation of America. EHCA includes two joint venture hospitals, Emory Eastside Medical Center and Emory Johns Creek Hospital. The Woodruff Health Sciences Center has a $2.3 billion budget, 18,000 employees, 2,500 full-time and 1,500 affiliated faculty, 4,300 students and trainees, and a $5.5 billion economic impact on metro Atlanta.

Ashante Dobbs | EurekAlert!
Further information:
http://www.emory.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>