A team of University of California, San Diego physicists and neuroscientists has discovered a bottleneck in the network of blood vessels in the brain that makes it vulnerable to strokes. The finding may explain the origin of the puzzling damage to the brain?s gray matter often detected in brain scans, especially among the elderly.
In the study, published this week in the journal Proceedings of the National Academy of Sciences, the researchers used a laser technique they developed to precisely monitor changes in blood flow resulting from an induced blockage in a tiny artery, or arteriole, in the brains of anesthetized rats. They found that the penetrating arterioles, which connect the blood vessels on the brain?s surface with deeper blood vessels, are a vulnerable link in the network.
?The blood vessels on the surface of the brain are like a collection of city streets that provide multiple paths to get somewhere,? explained David Kleinfeld, a professor of physics at UCSD, who led the team. ?If one of the vessels is blocked, blood flow quickly rearranges itself. On the other hand, the penetrating arterioles are more like freeways. When blocked, the blood flow is stopped or slowed significantly in a large region round the clot.?
Nishimura was the first author on the study and is now a postdoctoral fellow at Cornell University working with Chris Schaffer, an assistant professor of biomedical engineering. Schaffer, who also contributed to the study, was an assistant project scientist working with Kleinfeld and Lyden at the time of the discovery.
The study was supported by the National Institutes of Health and the National Science Foundation.