Run your way to a better 'memory'

If you have trouble remembering where you left your car keys or struggle to recall people's names, you may want to start pounding the treadmill. A new study has suggested that running can help boost your brain power.

The reason why treadmill training can boost memory recall remains an active area of investigation. A couple of proteins have been shown to fuel exercise-induced neuron growth, but the study presents a new candidate, cathepsin B, one that can be directly traced from the muscles to the brain in mice. Also, after a run, protein levels increased in blood in mice, monkeys, and humans.

"We wanted to cast a wide net. Rather than focus on a known factor, we did a screen for proteins that could be secreted by muscle tissue and transported to the brain, and among the most interesting candidates was cathepsin B," said senior author Henriette van Praag.

She and her team conducted a series of experiments on mice to test the memories of those lacking the protein compared to normal mice. Over the course of a week, both groups were given a daily swim test in a water maze. The animal is placed in a small pool ad must learn to swim to a platform that is hidden just below the surface of the water.

After doing the task for a few days, those with normal levels of the protein eventually learn where to find the platform. However, when both groups ran before their daily swim test, the normal mice were better able to recall the location of the platform. But those unable to make cathepsin B could not remember its location.

Going forward, the researchers want to better understand how cathepsin B is crossing the blood-brain barrier and how it is activating neuronal signalling, growth, and connections. There are also questions around whether the protein behaves the same in different species, and how production of cathepsin B changes with age.

"Overall, the message is that a consistently healthy lifestyle pays off," van Praag says. "People often ask us, how long do you have to exercise, how many hours? The study supports that the more substantial changes occur with the maintenance of a long-term exercise regimen."

The study appears in Cell Metabolism.