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12 December 2013 1:00 pm ,
Vol. 342 ,
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
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Alzheimer's Protein Dements Flies
14 June 2001 7:00 pm
In Alzheimer's disease and related dementias, neurons die stuffed with cellular debris, consisting mainly of a protein called tau. Now a new fruit fly burdened with tau loses brain cells when it gets old. The model could help uncover new clues about how tau might torpedo neurons.
Tau normally stabilizes neuron microtubules, a kind of rail system that runs through neurons and helps transport molecules to nerve endings. In Alzheimer's and other diseases, tau proteins clump together into tangles. Some researchers speculate that neurons are killed by tangles that gum up their internal works, although others suggest that free-floating tau does the damage, perhaps by causing oxidative damage or urging cells to kill themselves.
To find out how tau damages neurons, neuropathologist Mel Feany of Harvard Medical School in Boston and her colleagues introduced into fruit flies either the normal human tau gene or a mutant version responsible for another type of tau-related dementia. The researchers then watched what happened to the nervous systems of the transgenic flies as they aged. Brain cells in day-old flies were fine, but neurons in doddering 30-day-old flies had disintegrating nuclei and other organelles. "We saw them falling apart," Feany says. Both tau proteins especially damaged neurons that communicate using the neurotransmitter acetylcholine--a group of cells that are also hit heavily in Alzheimer's disease. Surprisingly, however, the dying neurons didn't contain any tangles, the researchers report in work published online by [http://www.sciencexpress.org] Science on 14 June.
It's "very elegant, nicely done work," says Zaven Khachaturian, senior scientific adviser to the Alzheimer's Association. But some experts caution that the lack of tangles might mean that flies aren't a good model of human dementias. "The worry is that cells are dying by a different mechanism than neurons do when they make tangles in Alzheimer's disease," says neuroscientist John Hardy of the Mayo Clinic in Jacksonville, Florida.