Word: humanity
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Dates: during 1990-1999
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...cure, a host of neurological diseases such as Parkinson's and Alzheimer's, as well as brain damage caused by strokes and head injuries. Even a year ago, such a sweeping claim might have been dismissed as nonsense. But that was before last fall's discovery that the fetal human brain contains master cells (called neural stem cells) that can grow into any kind of brain cell. Snyder extracted these cells and "mass-produced" them in the lab. His hope is that the cells, when injected into a damaged adult brain, will turn themselves into replacements for cells that...
...brain of an adult canary has the astonishing ability to regenerate new nerve cells at a rate of up to 20,000 a day. Other researchers reported similar regenerative ability in fish and reptiles, but there was still no evidence that evolution had passed on this ability to the human brain. Indeed, most neuroscientists wouldn't even entertain the possibility of new cell growth in the human brain on the grounds that any additional cells would disrupt the brain's complex wiring...
Snyder was not so sure. "I'm an optimist. Why would evolution have been parsimonious in depriving the human brain of the power of self-healing? I was a pediatrician before I became a neuroscientist. As a pediatrician, I was impressed by how much plasticity there really must be in the human brain. Pediatricians know that damage to the infant brain doesn't have the same outcome as damage to the adult brain. If a newborn has a stroke, even in the cortex [an area important to higher intellectual functions], he or she may sustain it and develop quite normally...
...marmoset monkeys and rhesus monkeys, all of which are closer to us on the evolutionary scale than are mice (except in Kansas). The real payoff came late last year, when Fred Gage at the Salk Institute and his colleagues in Sweden reported that nerve cells are regenerated in the human hippocampus (a portion of the brain related to memory and learning...
Gage's finding--coupled with Snyder's report that same month of stem cells in the fetal human brain--has stood neuroscience on its head, so to speak. As has the latest finding, announced last month by researchers at Princeton, that adult macaque monkeys are constantly growing new cells in the highest and most complex area of the brain, the cerebral cortex. Snyder is now flush with confidence that neuroscience will ultimately cure many, if not all, diseases of the human brain. "By the year 2020 I hope we will have an active way of treating damaged brains...