Gene Therapy Restores Aged Primate Brains to Youthful Vigor
Feb. 12, 2001 -- It's not exactly the Fountain of Youth -- and it's only been shown to work in monkeys -- but new reports suggest that gene therapy can successfully restore both brain cells and their connections to the brain's center of learning and memory in aged primates. The potential is there, though, for the same therapy to succeed at halting or even reversing the mental decline seen in people with Alzheimer's disease.
"We really don't know what happens in the brain with aging," says researcher Mark Tuszynski, MD, PhD, in an interview with WebMD. It's clear we experience a reduction in cognitive function -- the ability to learn, think, and remember -- and researchers have believed this to be connected to loss of brain cells, he explains.
More recently, though, he says, a number of studies, including some of his own, have shown that, actually, "there's very little, if any, cell death in the brain with aging. But there are problems in brain function with aging."
As Tuszynski and colleagues showed in a previous study (also with monkeys), about 40% of brain cells that transmit a chemical essential for learning and memory appear to shrink and lose their normal abilities with age. The cells, called cholinergic nerve cells, produce the chemical acetylcholine.
The researchers also found that by transplanting skin cells -- that had been genetically altered to produce a substance called nerve growth factor -- into the brains of elderly monkeys, they could restore shrunken brain cells to about the same size and number as seen in younger animals.
They have now taken their work a step further, as reported in the Feb. 13 issue of the journal Proceedings of the National Academy of Sciences. Not only do the nerve growth factor-producing cells freshen up these cholinergic cells and restore them to youthful levels, but they also help restore the connections that send signals from the nerves to the learning and memory centers of the brain. Surprisingly, they also found that when the genetically altered cells were implanted directly next to the shrunken nerve cells, the nerve growth factor encouraged the growth of new connections -- both in the immediately adjacent cells and in cells some distance away.
Gene Therapy Restores Aged Primate Brains to Youthful Vigor
Feb. 12, 2001 -- It's not exactly the Fountain of Youth -- and it's only been shown to work in monkeys -- but new reports suggest that gene therapy can successfully restore both brain cells and their connections to the brain's center of learning and memory in aged primates. The potential is there, though, for the same therapy to succeed at halting or even reversing the mental decline seen in people with Alzheimer's disease.
"We really don't know what happens in the brain with aging," says researcher Mark Tuszynski, MD, PhD, in an interview with WebMD. It's clear we experience a reduction in cognitive function -- the ability to learn, think, and remember -- and researchers have believed this to be connected to loss of brain cells, he explains.
More recently, though, he says, a number of studies, including some of his own, have shown that, actually, "there's very little, if any, cell death in the brain with aging. But there are problems in brain function with aging."
As Tuszynski and colleagues showed in a previous study (also with monkeys), about 40% of brain cells that transmit a chemical essential for learning and memory appear to shrink and lose their normal abilities with age. The cells, called cholinergic nerve cells, produce the chemical acetylcholine.
The researchers also found that by transplanting skin cells -- that had been genetically altered to produce a substance called nerve growth factor -- into the brains of elderly monkeys, they could restore shrunken brain cells to about the same size and number as seen in younger animals.
They have now taken their work a step further, as reported in the Feb. 13 issue of the journal Proceedings of the National Academy of Sciences. Not only do the nerve growth factor-producing cells freshen up these cholinergic cells and restore them to youthful levels, but they also help restore the connections that send signals from the nerves to the learning and memory centers of the brain. Surprisingly, they also found that when the genetically altered cells were implanted directly next to the shrunken nerve cells, the nerve growth factor encouraged the growth of new connections -- both in the immediately adjacent cells and in cells some distance away.
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