( New findings that long-overlooked brain...)Blood flow in brain takes a twist, affecting views of Alzheimer's

In a paper to appear in the February issue of Nature Neuroscience and now available on-line, scientists at the University of Rochester Medical Center demonstrate that star-shaped brain cells known as astrocytes play a direct role in controlling blood flow in the brain, a crucial process that allows parts of the brain to burst into activity when needed. The finding is intriguing for a disease like Alzheimer's, which has long been considered a disease of brain cells known as neurons, and certainly not astrocytes.

"For many years, astrocytes have been considered mainly as housekeeping cells that help nourish and maintain a healthy environment for neurons. But it's turning out that astrocytes may play a central role in many human diseases," said neuroscientist Maiken Nedergaard, M.D., Ph.D., who has produced a string of publications fingering astrocytes in diseases like epilepsy and spinal cord injury.

"In a disease like Alzheimer's, for instance, perhaps it's the astrocytes themselves that are damaged first," she said. "It may be that for whatever reason, astrocytes are not doing their job properly, and then blood flow decreases. This could lead to the death of the neurons, which would starve from a lack of nutrients, since the neurons depend on the astrocytes for their survival."

The new research focuses on a process critical to the health of people with Alzheimer's and everyone else: the moment-to-moment allocation of vital resources like oxygen that goes on within our bodies. It's a supply problem familiar to anyone who worried over the availability of gasoline immediately after hurricane Katrina. In our bodies the process is particularly cr
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Source:University of Rochester Medical Center