The human brain was long thought to hold a finite number of nerve cells that, once lost, could never be regained. Now, contrary to that long-held belief, findings from a study suggest that nerve cells in the adult human brain can regenerate. If researchers can find a way to stimulate this process, they may be able to treat illness caused by the death of brain cells, such as Parkinson's and Alzheimer's disease. The study demonstrates that cell genesis occurs in human brains and that the human brain retains the potential for self-renewal throughout life. The researchers note that the biological significance of cell growth in the brain is not clear. However, they suggest that the presence of such cells opens avenues of research that could lead to new therapeutic approaches. The finding is still a few steps removed from practical application. But it might be possible to find a way to reactivate the genes that were active during development and start the whole process of cell division over again. Or it may be possible to grow such nerve cells in the laboratory and transplant the cells or deliver them into the brains of those who may benefit.
Nature Medicine 1998;11:1313-1317
COMMENT: I am constantly amazed at how regularly a rigid "truth" in science changes.