5/29/2010 PERMALINK
As you age the tiny blood vessels in your brain lose their ability to expel debris. Northwestern University Feinberg School of Medicine : Scientists have discovered capillaries have a unique method of expelling debris, such as blood clots, cholesterol or calcium plaque, that blocks the flow of essential nutrients to brain cells. The capillaries spit out the blockage by growing a membrane that envelopes the obstruction and then shoves it out of the blood vessel. Scientists also found this critical process is 30 to 50 percent slower in an aging brain and likely results in the death of more capillaries. 'The slowdown may be a factor in age-related cognitive decline and may also explain why elderly patients who get strokes do not recover as well as younger patients,' said Jaime Grutzendler, senior author and principal investigator of the study and assistant professor of neurology and of physiology at Feinberg. 'Their recovery is much slower.'