Can a regular work-out help counter the effects of aging on the brain? – photo ©iStockphoto/lisay
UBC Reports | Vol. 53 | No. 6 | Jun 7, 2007
By Hilary Thomson
Can being buff make you brainy?
That’s what UBC neuroscientist Brian Christie is trying to find out. He investigates biological mechanisms that help the brain create new cells, or neurons, as a result of exercise.
He is especially interested in how exercise can help generate new cells in the adult brain. His findings offer hope of cellular repair and replacement in conditions such as Alzheimer’s disease, stroke, schizophrenia, Attention Deficit Hyperactivity Disorder and Fetal Alcohol Syndrome.
Christie, an associate professor in the division of neuroscience and a member of the Brain Research Centre at UBC Hospital, was one of the first researchers to discover that exercise promotes the birth of brain cells, a process called neurogenesis, in the hippocampus — an area of the brain involved with learning and memory.
The research team believes there are several components to the effects of exercise. It increases blood flow to the brain, bringing additional oxygen and other nutrients. Also, exercise changes the metabolism in the brain, making neurons and their receptor proteins more efficient. Receptor proteins allow cells to recognize chemical messengers and are key to learning and memory. In addition, exercise also facilitates the production of other chemicals, called neurotrophins, that help promote neuron survival.
“I didn’t believe our results at first,” says Christie of his 1999 study. “I actually ended up running the entire experiment twice just to make sure that we were indeed seeing all of these benefits.”
He also found that exercise promotes synaptic plasticity, the ability of the synapse – the parts of neurons where information flows from one cell to another – to allow neurons to communicate with one another. Improved synaptic plasticity means greater efficiency and effectiveness in communication between nerve cells with resulting gains in brain function.
In 2005, Christie, who is also a member of the Vancouver Coastal Health Research Institute (VCHRI), found that exercise could also repair parts of the brain damaged by prenatal exposure to alcohol.
“The findings go against everything I was taught as a undergrad,” he says. “Rather than an unchanging circuit board, some regions of the brain are more like small, dynamic ecosystems — the better we take care of them, the better they function.”
Now he is investigating effects of exercise on the aging hippocampus, in animal models.
Normal aging means loss of brain cells and branches of cells called dendrites that allow communication between cells. In humans, these losses start around age 60-65.
Christie is focused on the continual introduction of new neurons into the adult brain via exercise and how they integrate into the existing neural architecture to promote better learning and memory.
Christie’s research also uses animal models that mimic functional impairment seen in Alzheimer’s disease, stroke and dementias such as Down syndrome. He has found that exercise in adults not only creates new neurons in the hippocampus, it also increases the number of synapses and the complexity of dendrites. It all adds up to increased computational power for learning and memory.
So how much exercise is needed? Only about 20-30 minutes of brisk walking a day, says Christie. But don’t think running a daily marathon will make you a genius or cure a brain disease.
“Exercise can’t cure disease, but we’ve seen that it can retard the progression of major illnesses and preserve our mental capacity. And it’s never too late to start.”
VCHRI is the research body of Vancouver Coastal Health and the fourth largest research institute in Canada. In academic partnership with UBC, VCHRI brings innovation and discovery to patient care, advancing healthier lives in healthy communities across British Columbia, Canada, and beyond.
Christie’s research is supported by the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council, the Human Early Learning Partnership, the Alcohol Board for Medical Research and the Scottish Rites Charitable Foundation.
