Featured Research

from universities, journals, and other organizations

Mouse Model Of Parkinson's Reproduces Nonmotor Symptoms

Date:
June 30, 2009
Source:
Emory University
Summary:
Nonmotor symptoms of Parkinson's include digestive and sleep problems, loss of sense of smell and depression. A mouse with a mutation in a gene responsible for packaging neurotransmitters like dopamine and norepinephrine reproduces the major non-motor symptoms as well as motor symptoms. The finding sheds light on nonmotor symptoms' causes and their relationship with the neurodegeneration seen in Parkinson's.

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.

Related Articles


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.


Story Source:

The above story is based on materials provided by Emory University. Note: Materials may be edited for content and length.


Journal Reference:

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

Cite This Page:

Emory University. "Mouse Model Of Parkinson's Reproduces Nonmotor Symptoms." ScienceDaily. ScienceDaily, 30 June 2009. <www.sciencedaily.com/releases/2009/06/090623091123.htm>.
Emory University. (2009, June 30). Mouse Model Of Parkinson's Reproduces Nonmotor Symptoms. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2009/06/090623091123.htm
Emory University. "Mouse Model Of Parkinson's Reproduces Nonmotor Symptoms." ScienceDaily. www.sciencedaily.com/releases/2009/06/090623091123.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How To: Mixed Green Salad Topped With Camembert Cheese

How To: Mixed Green Salad Topped With Camembert Cheese

Rumble (Jan. 26, 2015) Learn how to make a mixed green salad topped with a pan-seared camembert cheese in only a minute! Music: Courtesy of Audio Network. Video provided by Rumble
Powered by NewsLook.com
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Husky Puppy Plays With Ferret

Husky Puppy Plays With Ferret

Rumble (Jan. 26, 2015) It looks like this 2-month-old Husky puppy and the family ferret are going to be the best of friends. Look at how much fun they&apos;re having together! Credit to &apos;Vira&apos;. Video provided by Rumble
Powered by NewsLook.com
Scientists Model Flying, Walking Drone After Vampire Bats

Scientists Model Flying, Walking Drone After Vampire Bats

Buzz60 (Jan. 26, 2015) Swiss scientists build a new drone that can both fly and walk, modeling it after the movements of common vampire bats. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins