In a dramatic challenge to previous neurological theory, results of studies in monkeys suggest that new brain cells are added to the primate brain each day. Besides shedding new light on learning and memory, the findings could someday lead to new treatments for a host of degenerative brain diseases. According to traditional scientific theory, the human brain was thought to be incapable of growing new cells or regenerating lost or damaged cells, explaining why severe brain injuries, for example, do not heal completely. However, recent research had suggested that the brains of more primitive animals, including songbirds, could grow new cells. The new findings suggest that this process may occur in primates -- including humans -- as well.
The research team believes that the introduction of new neurons into the brain may form the basis for marking the temporal dimension of memory -- in other words, the means by which we distinguish memories acquired last month from those of 20 years ago. If memories are formed from experiences, these experiences must produce changes in the brain. The findings may have implications for the prevention and treatment of various degenerative brain diseases, such as Alzheimer's and stroke-related dementia. It shows there are natural mechanisms in the brain that, someday, might be harnessed for therapeutic purposes to replenish damaged areas to the brain.
Science October 15, 1999;286:548-552.
COMMENT: It seems that some of the most cherished and founded medical principles that I was taught in medical school continue to fall by the wayside as time goes on.