Researchers at The Ottawa Hospital and the University of Ottawa have discovered that a molecule triggered by running can help repair certain types of brain damage in mice.

The molecule, called VGF nerve growth factor, had previously been discovered to promote an anti-depressant response, but its importance in preventing or delaying brain damage wasn't as clear.

But in a study published Tuesday in the scientific journal Cell Reports, the researchers discovered the production of VGF nerve growth factor assists with the healing of the protective coating that insulates nerve fibres.

The discovery was made when researchers were studying mice with genetically modified cerebellums, the part of the brain that controls motor movement co-ordination and balance.

Mice who ran lived over a year

Researchers found that mice with smaller cerebellums had difficulty walking and lived only 25 to 40 days. However, when they were allowed to run freely on a wheel, they lived for over a year.

"Once we saw this effect it was kind of our eureka moment and we did a lot of genetic analysis to identify the genes that were changed ... that could account for why they were surviving and then we honed in on one of these genes called VGF," said Dr. David Picketts, one of the authors of the study.

Dr. David Picketts

VGF nerve growth factor is important to kick-start healing in damaged areas of the brain says Dr. David Picketts. (CBC)

Picketts, a senior scientist at The Ottawa Hospital and a professor at the University of Ottawa, said the new research is especially interesting because it helps to explain the effect that exercises, like running, have on people suffering from neurodegenerative diseases that involve damaged nerve insulation like multiple sclerosis.

"Individuals that have inherited forms of cerebellar ataxia have difficulty walking and coordination so we sort of created a novel mouse model of that," Picketts said.

Benefits only lasted as long as exercise

"In this instance VGF helped increase the insulation on the neurons in the mice and allowed these neurons to continue functioning for longer than they normally would."


New research shows mice with smaller cerebellums that are given the opportunity to run freely live much longer than sedentary ones. (Robert F. Bukaty/Associated Press)

The research also showed that when mice stopped exercising they began to debilitate again.

"[VGF] is one of the first molecules, or pathways, that's been identified that can help understand how exercise can help delay the progression of these neurodegenerative disorders," said Picketts.

"[We're] beginning to identify some of these molecules and mechanisms that help understand why exercise is so good for you."