NASHVILLE, Feb. 5 -- For years, scientists have believed that brain cells can't be born or newly generated following a stroke. But a new study in rodents finds that some brain cells are actually stimulated to regenerate following a stroke, a discovery that opens the door to treating memory disorders in stroke patients.

According to the study, this is the first evidence of a certain type of brain cell -- called a stem cell -- demonstrating plasticity and the ability to regenerate after a stroke.

Regeneration is the ability of the stem cells to divide and produce new neurons. Plasticity is the ability of the newborn neurons to make connections with existing neurons in the brain and integrate into their surrounding cellular environment. Though other studies have shown that new neurons are born under other conditions, this is the first study to show that new brain cells are born following stroke. The research was performed by inducing stroke in rodents.

"Data show that new neurons are born in the brains of adult monkeys and in the brains of adult humans," says Frank Sharp, M.D., of the department of neurology, University of California-San Francisco and one of the study's investigators. "It is not known whether there are new neurons born in the brains of humans following stroke. We certainly think there would be."

In research presented at the presented today at the American Heart Associations 24th International Conference on Stroke and Cerebral Circulation, scientists at the University of California-San Francisco discovered as much as a 12-fold increase in the birth of new cells in rodents after stroke in an area of the brain -- the hippocampus -- which controls memory.

"This region is important for new memories," says Sharp. "If you lose this region of the brain, you're unable to remember new sights, sounds and other experiences. You might remember your mother and father or something you learned in
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Contact: Brian Henry or Cathy Yarbrough
615-231-1601
American Heart Association
5-Feb-1999