Brain injury due to motor vehicle accidents, falls, and sports accidents, among other reasons, affects nearly two million people every year, with related deaths claiming more than 56,000, according to the Brain Injury Association. Despite this, how the brain responds to injury -- in terms of the cellular cascade that leads to cell death -- is poorly understood. Looking at a particular pattern of cell death called apoptosis, or programmed cell death, researchers at the University of Pennsylvania Medical Center have discovered that in a rat model this kind of deleterious cellular destruction continues for weeks after the initial trauma.
"We hope that by understanding the molecular and cellular sequences of events after trauma, we'll be able to ascertain when and where cells die in the brain and use that information to develop new therapeutic strategies to treat injury," says Tracy K. McIntosh, PhD, professor of neurosurgery, bioengineering, and pharmacology. These insights could also apply to treating stroke, spinal cord injury, and perhaps neurodegenerative diseases. McIntosh and colleagues report their findings in the August 1 issue of the Journal of Neuroscience.
Classically, research in this field has focused almost exclusively on the first few days after an injury. Scientists hypothesized that this is when the maelstrom of neurochemical changes occurred, and after that, the brain's response calms down. "But this study points to the fact that things are not so quiet," comments McIntosh, who is also Director of Penn's Head Injury Center. "A brain-injured patient may look stable, but cells are still dying. Realizing this will be important for coming up with ways to recover, regenerate, and stem the loss of brain tissue. These findings could eventually effect protocols in rehabilitation and lead to ways to pharmacologically block cell death."
Alana C. Conti, a doctoral student in McIntosh's lab, charted the
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Contact: Karen Young Kreeger
University of Pennsylvania School of Medicine