Navigation Links
Cells talk more in areas Alzheimer's hits first, boosting plaque component
Date:5/2/2011

Higher levels of cell chatter boost amyloid beta in the brain regions that Alzheimer's hits first, researchers at Washington University School of Medicine in St. Louis report. Amyloid beta is the main ingredient of the plaque lesions that are a hallmark of Alzheimer's.

These brain regions belong to a network that is more active when the brain is at rest. The discovery that cells in these regions communicate with each other more often than cells in other parts of the brain may help explain why these areas are frequently among the first to develop plaques, according to the researchers.

Working with mice genetically engineered to develop Alzheimer's type-brain changes, scientists reduced the size and number of plaques by decreasing brain cell activity in certain regions.

The results, appearing May 1 in Nature Neuroscience, are the latest to hint at a resolution to lines of evidence that have suggested busier brain cells can both contribute to and prevent Alzheimer's. According to a new theory, which brain cells are kept busy may make all the difference.

"Engaging the brain in tasks like reading, socializing or studying may be helpful because they reduce activity in susceptible regions and increase activity in regions that seem to be less vulnerable to Alzheimer's plaque deposition," says David M. Holtzman, MD, the Andrew B. and Gretchen P. Jones Professor and head of the Department of Neurology. "I suspect that sleep deprivation and increased stress, which may affect Alzheimer's risk, may also increase activity levels in these vulnerable regions."

The susceptible regions of the brain highlighted in the new study belong to the default mode network, a group of brain regions that become more active when the brain is not engaged in a cognitively demanding task. Co-author Marcus Raichle, MD, professor of neurology, of radiology and of neurobiology, was among the first to describe the default mode network.

In a paper published in 2005, Washington University researchers showed that regions in the default mode network are often among the first to develop Alzheimer's plaques. To understand why, Adam Bero, a graduate student in Holtzman's lab, analyzed the brain chemistry of mice. He found that the mouse brain regions analogous to those in the human default mode network had similarly high levels of early amyloid plaque deposits when compared to other areas.

Next, Bero showed in younger mice that the high-plaque regions had increased amyloid beta levels. In a third experiment, he found that the greater amyloid beta levels were caused by increased nerve cell communication in the affected regions.

To further prove the relationship between plaque formation and cell communication, scientists trimmed the whiskers on one side of a group of mice and kept them short for one month.

"Because mice are nocturnal and their eyesight is poor, whiskers are an important way for them to sense where they are in their environment," Holtzman explains. "By cutting the whiskers back on one side, we reduced neuronal activity in the region of the brain that senses whisker movement."

Loss of this input resulted in smaller and less numerous plaques on the side of the brain connected to the pruned whiskers. In a separate experiment, when researchers regularly stimulated whiskers with a cotton swab, amyloid beta levels increased.

According to Holtzman, the results demonstrate the direct connection between amyloid plaque formation and growth and changes in brain cell activity levels in various parts of the brain. He plans further investigations of the mechanisms that regulate default brain activity, their connections to phenomena such as sleep, and their potential effects on Alzheimer's disease.


'/>"/>

Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
Source:Eurekalert  

Related medicine news :

1. New Study Uses Adult Stem Cells in Effort to Save Limbs of Patients with Peripheral Arterial Disease
2. New study suggests stem cells sabotage their own DNA to produce new tissues
3. Attacking cancer cells with hydrogel nanoparticles
4. UCR researcher identifies mechanism malaria parasite uses to spread in red blood cells
5. Pittsburgh Neurosurgeons Explore Use of Drug that Illuminates Brain Tumor Cells To Guide Surgery
6. New tool illuminates connections between stem cells and cancer
7. Bitter melon extract attacks breast cancer cells
8. Heart Stem Cells Move Closer to Human Treatments
9. Notch-blocking drugs kill brain cancer stem cells, yet multiple therapies may be needed
10. Cells of aggressive leukemia hijack normal protein to grow
11. Periodontal pathogens enhance HIV-1 promoter activation in T cells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Cells talk more in areas Alzheimer's hits first, boosting plaque component
(Date:1/21/2017)... ... January 21, 2017 , ... Phytocéane invites ... isolated from the rest of the world with ZANZIBAR SHOWER GEL. Inspired by the ... key ingredients, Virgin Coconut Oil and moisturizing vegetal coral to create this gentle, crystal-clear ...
(Date:1/21/2017)... ... 21, 2017 , ... The Nobel Biocare™ dental implant company ... for its creos™ line of bone regenerative products. Specifically, the Nobel ... utilizes creos™ allo.gain™ bone graft for a variety of bone reconstruction procedures. In ...
(Date:1/20/2017)... ... January 20, 2017 , ... Doctor C LLC, a ... the January ECRM trade show to continue the marketing and distribution of its product, ... known for providing 400 percent better absorption than traditional vitamin C supplements. At the ...
(Date:1/20/2017)... ... January 20, 2017 , ... Michael and Betsy Brauser celebrated 5 years of ... the clinical trial has been life-saving as she has been on the trial ... Brauser was diagnosed with ovarian cancer in 2009. She underwent standard chemotherapy but a ...
(Date:1/20/2017)... ... ... Chocolate Biscuit”: a biographical account following a man who went on to support his country ... Ivey, born in Lynn Haven, Florida and at the age of 5, his family moved ... he joined the Navy and got married right out of boot camp. , He ...
Breaking Medicine News(10 mins):
(Date:1/20/2017)... -- Entscheidung fällt als Reaktion ... Die internationale humanitäre Stadt soll um knapp 2800 m² erweitert ... Seine Hoheit Scheich Muhammad bin Raschid Al ... Dubai , hat den Auftrag erteilt, ... City IHC) zu verdreifachen, um den Betrieb zur Unterstützung ...
(Date:1/19/2017)... -- Report Details What can be expected ... to grow at the fastest rates? This visiongain report ... opportunities and prospects. Our 190-page report provides 124 ... in the industry and the future market prospects. Our ... all the major categories of the ophthalmic devices market. ...
(Date:1/19/2017)... Jan. 19, 2017 Report Details ... Alzheimer,s ... Leading Companies – our new study reveals trends, R&D ... and events affecting the Alzheimer,s disease therapeutics and diagnostics ... these key questions: - How is the Alzheimer,s disease ...
Breaking Medicine Technology: