By IANS,
Washington : Spelling new hope for Alzheimer’s disease and stroke patients, researchers have identified a protective mechanism in mice that helps the tiniest blood vessels remove clots and other blockages from the brain.
Uninterrupted blood flow is critical for brain function, and the brain has developed various mechanisms to maintain it.
Blockages in the smallest blood vessels can be cleared by processes that disintegrate or wash them out. However, not all blockages are cleared completely.
Persistent blockage can reduce or stop blood flow, limiting the supply of oxygen and nutrients to the surrounding tissue and nerve cells. This, in turn, can lead to impaired communications between nerve cells and ultimately cell death.
Jaime Grutzendler of Northwestern University Feinberg School of Medicine (NUFSoM), who led the study, used a newly developed imaging technique that can peer into the tiniest blood vessels, known as micro-vessels, in live mice brains.
They found that two to seven days after a blockage in brain microvessels, the cells lining the blood vessel wall engulf the remaining portion of the blockage, encapsulate it, seal it off from the interior of the blood vessel and finally expel the blocking material.
As a result of this process, blood flow is restored to the affected area.
“These are intriguing findings,” said National Institute of Aging (NIA) director Richard J. Hodes. “They open new avenues of basic research that may increase our understanding of how microvessels are maintained in the brain and throughout the body.”
Researchers also found that the ability to move the blockage out of the blood vessel diminished with age. Young mice (four months) were able to clear blockages more quickly and thoroughly than older mice ( 22 months), said a NUFSoM release.
“This may also be part of the mechanism by which vascular risk factors such as high blood pressure and diabetes increase the risk of Alzheimer’s disease with age,” said Suzana Petanceska, Neurobiology of Aging Branch in NIA Division of Neuroscience.
These findings were published in Thursday’s edition of Nature.