By Emily Willingham
The drumbeat of exercise’s brain benefits may sound familiar. Most of us know that getting our move on can mean a boost to mental and neurological health. But what if, through understanding these biochemical processes, we could get all of that brain gain without going through the exercise pain? Mouse experiments have already demonstrated the feasibility of such a shortcut. And there is a hint that the results in rodents could work in humans as well.
When plasma from well-exercised mice is injected into their idling counterparts, the sedentary rodents have improved memory and reduced brain inflammation. The blood of Olympic athletes is not about to be transfused into the arms of sofa spuds—at least not yet. But people with mild cognitive impairment who exercise for six months show increases in a key protein identified in the runner-mouse plasma. The same protein may be able to whisper its chemical message across the notoriously choosy blood-brain barrier and trigger anti-inflammatory processes in the brain.
These findings, published on December 8 in Nature, offer new details of how exercise benefits the brain and how molecules boosted by physical activity communicate across the organ’s strict gatekeeper. The results also hint at a surprising role for the liver and anticlotting systems in these effects and possibly point the way to a futuristic scenario of exercise in a pill—or perhaps a plasma injection.