Word: brained
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Dates: during 2000-2009
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Something else is going on as we get older that also impairs memory: our brains are making fewer neurons. Until a decade ago, the common assumption was that we were born with a fixed number of brain cells that die off as we age, making us, well, dimmer. That, however, is not the case. It is now known that the brain continues to produce neurons throughout the life cycle, but only in two places: the olfactory bulb and the hippocampus. And not just anywhere in the hippocampus but in the dentate gyrus, the very node that Small has identified...
...decade ago, when neuroscientist Fred Gage of the Salk Institute made the discovery that the adult brain continues to regenerate, the brains in question belonged to mice. Some of the mice had been sedentary, others had been exercising, and the ones that logged the most miles on their wheels produced many more new neurons than did the sedentary ones...
...Kramer at the University of Illinois and others at Israel's Bar-Ilan University, investigators found that those who engaged in aerobic exercise did better cognitively than those who stretched and toned but never got their heart rates pumping. What's more, subsequent imaging showed that aerobic exercise "increased brain volume in regions associated with age-related decline in both structure and cognition...
Cerebral blood volume is not the only thing responsible for this brain-boosting. Also at work is the fact that exercise increases what's known as brain-derived neurotrophic factor (BDNF), a protein that stimulates the birth of new brain cells and then helps them differentiate and connect. BDNF also enhances neural plasticity, the process by which the brain changes in response to learning. In diseases like Alzheimer's, depression, Parkinson's and dementia, BDNF levels are low. In people who exercise, BDNF levels rise...
...Watching the junior Senator from New York, I was of two minds. My high-minded policy brain was, of course, appalled. The gas-tax holiday was a scam. It had been tried at various times - Barack Obama had voted for a local version in the Illinois legislature - and prices never came down. The oil companies and gas-station owners simply pocketed the difference. Clinton's "responsible" version of the plan was also a scam. She wanted to pay for it with a "windfall profits" tax on the oil companies, but she had earlier, and more responsibly, called for the elimination...