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 Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>