Running triggers brain repair and extends life in mouse model - Medical News TodayThe researchers allowed some of the mice the opportunity to run by installing a wheel into their cages. Surprisingly, the mice given the opportunity to run lived more than 12 months (a relatively normal lifespan for a mouse). On top of their extended lives, the running mice also put on more weight and achieved a better sense of balance, compared with their less active siblings. "We saw that the existing neurons became better insulated and more stable. This means that the unhealthy neurons worked better and the previously damaged circuits in the brain became stronger and more functional." Dr. Matías Alvarez-Saavedra, lead author However, these changes were reversed if the opportunity to exercise was taken away. Once the running wheel was removed, the symptoms returned, and their lives were once more cut short.
Odds are good that risky gambling choices are influenced by a single brain connection -- ScienceDailyUsing that technique, called diffusion-weighted MRI, Knutson and graduate student Josiah Leong found a tract that directly connects the anterior insula and nucleus accumbens -- something that had been seen before in animals but never in humans. What's more, they found that the thicker the sheath of fatty tissue insulating the bundle -- an indicator of the strength of the connection -- the more cautious the study participants' decisions were in a gambling test. The neuronal connection appears to be a conduit for the more cautious brain region to dampen activity in the more enthusiastic region. "Most people love the small chance of a huge win," Knutson said. "But people vary. Some people really, really like it. But people who have a stronger connection don't like it as much."
Meanwhile, in times of doubt, take inspiration in one last distinction of the teen brain—a final key to both its clumsiness and its remarkable adaptability. This is the prolonged plasticity of those late-developing frontal areas as they slowly mature. As noted earlier, these areas are the last to lay down the fatty myelin insulation—the brain's white matter—that speeds transmission. And at first glance this seems like bad news: If we need these areas for the complex task of entering the world, why aren't they running at full speed when the challenges are most daunting? The answer is that speed comes at the price of flexibility. While a myelin coating greatly accelerates an axon's bandwidth, it also inhibits the growth of new branches from the axon. According to Douglas Fields, an NIH neuroscientist who has spent years studying myelin, "This makes the period when a brain area lays down myelin a sort of crucial period of learning—the wiring is getting upgraded, but once that's done, it's harder to change."