Studies are piling up showing how exercising your body boosts the fitness of you brain as well. Exercise has documented benefits for learning and memory, executive decision making function, mood regulation, and even protection against brain injury from an accident.

The latest piece comes from Dr. Ronald Duman's group at Yale, just published in Nature Medicine. Using a high tech screening approach, researchers looked at how certain genes change their activity levels in the brain after exercise.

Working out Your Brain

Specifically, they looked at a part of the brain called the hippocampus, which has known roles in learning and memory, the regulation of stress, and is one of the brain regions targeted by anti-depressants.

In the study, researchers gave mice either free access to exercise wheels in their cages or not. The study revealed that several genes increase their activity in the hippocampus following a week of voluntary exercise.

One gene that dramatically increased its activity was VGF, or vascular growth factor. This gene was originally named for its role in inducing new blood vessel growth but we now know that it has other roles as well. It's not known if increased blood supply to parts of the brain are involved in the exercise benefit, but I suspect that it probably is.

Beyond its potential blood flow benefits, VGF is interesting because it belongs to a larger family of growth factors that we already suspected to play roles in depression. Growth factors are involved in the growth and maintenance of all kinds of things, including neurons and blood vessels.

Depressed Mice?

Believe it or not, using carefully designed studies, researchers can actually evaluate depression-like behaviors in mice. When the authors of the new study looked at these behaviors, they found that the exercised mice showed fewer depressive behaviors than their non-exercised controls.

This shows that exercise helps alleviate depression behavior (which we already knew) but does not show that it was due to the increases in VGF activity. However, further studies by the group showed that injecting VGF into the animals had the same anti-depressive affects as exercise. Furthermore, when they looked at other mice that have naturally low VGF activity, they found that these mice had increased depressive-like behaviors.

This provides strong evidence that VGF plays a role in mediating the anti-depressive affect of exercise.

I'm sure that pharmaceutical companies are now looking at VGF related compounds for new anti-depressants. But the point of this article is not to suggest that you can get all the benefits of exercise by injecting VGF (It's not available anyway, yet).

The point is that exercise is incredibly beneficial to your brain and body. VGF is just one example of many protective systems turned on by exercise.

Just Move

In our part of the world, we're moving into the winter, making it more difficult to get outside and run around. But there are still many things that you can do to keep your brain and body fit through the cold months.

You could: join a gym, get exercise equipment into your house (and use it), buy an exercise tape or DVD, join a recreational volleyball or basketball program or other sport you enjoy; take a local fitness class or just brave the weather and go for a brisk walk.

Making exercise a habit will help you keep your brain healthy throughout life. Many people today don't get much exercise once they reach middle age. This may have been fine 100 years ago when the average life expectancy was about 55. Today, many of us will likely live past 80 or 90 years old. How many years do you have left? How many of those years to you want to have a healthy brain?