No Stress – If you excercise?

Researchers at Princeton University recently made a remarkable discovery about the brains of rats, which exercise. Their neurons or some of them respond differently to stress than the neurons of lazy rats. Scientists have known before that exercise stimulates the creation of new brain cells (neurons) but not how, these neurons may be functionally different from other brain cells one could argue.
In the experiment, preliminary results of which were presented last month at the annual meeting of the Society for Neuroscience in Chicago, scientists allowed one group of rats to run for some time. Another set of rodents was not allowed to exercise, but yet stand still waiting. Then all of the rats swam in cold water, which they don’t like to do. Afterward, the scientists examined date on the animals’ brains. They found that the stress of the swimming activated neurons in all of the animals’ brains. (Researchers could tell what neurons that were activated because the cells on specific genes in response to the stress.) But the youngest brain cells in the running rats, the cells that running created scientists assumed, were less likely to express the genes. They remained quiet. The cells born from running, the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm.
Exercise, an activity, might directly affect mood and anxiety, psychological states, was unclear. Thanks to improved research techniques and a growing understanding of the biochemistry and the genetics of thought itself, scientists begin to find out how exercise remodels the brain, making it more stress-resistant.
“It looks more and more like the positive stress of exercise prepares cells and structures and pathways within the brain so that they’re more equipped to handle stress in other forms,” says Michael Hopkins, a graduate at Dartmouth.
In the University of Colorado experiments, rats that ran for 3 weeks did not show much reduction in stress-affected anxiety, but those that ran for 6 weeks did. “Something happened between three and six weeks,” says Benjamin Greenwood, Ph.D.