University of Lethbridge neuroscientists are investigating whether early brain injuries can permanently alter the way genes work in the brain and predispose people to dementia as they age.
Evidence suggests that brain injury early in life, including concussion, may contribute to later dementia, says neuroscientist Robert Sutherland. He and his colleagues at the Canadian Centre for Behavioral Neuroscience want to know why.
The experiments, although still in laboratory animals, could help explain why some athletes who suffered repeated concussions, such as former National Hockey League player Reggie Fleming, developed a distinctive type of brain damage and symptoms similar to Alzheimer's disease.
Dr. Sutherland is part of a team that includes Bryan Kolb, Robbin Gibb, Robert McDonald and Olga Kovalchuk. The researchers are looking at how brain injuries influence the chemical switching system that activates and deactivates genes in the brain, or what's known as the epigenetics of brain injuries.
Thousands of genes are active in the brain and each produces one of the proteins that are essential for memory, learning, keeping brain cells alive and working, and for repairing damage.
The hypothesis is that brain injuries may trigger permanent changes to the switching system, Dr. Sutherland said. This results in either too much or too little of particular protein getting produced, which over the years can lead to problems or perhaps even changes in the architecture of the brain that might make someone more vulnerable to dementia.
The Lethbridge scientists look for these chemical changes in the genes of rats with the help of sophisticated equipment purchased with an $8-million grant from the Canadian Foundation for Innovation.
They have begun to study rats that have had mini-strokes or have been deprived of oxygen and they are planning to do similar work with rats that have had concussions.
"I am confident the same rules apply," Dr. Sutherland said.
Concussions, also known as mild traumatic brain injuries, occur when the brain moves or rotates inside the skull and different parts of the brain move against each other. Symptoms include headache, amnesia and confusion and can last for days, weeks or months.
Pittsburgh Penguins star Sidney Crosby hasn't played hockey since he suffered two hits to the head in early January.
While athletes who suffer concussions usually recover, and eventually return to hockey, football or other sports, there is growing evidence that some pay a high price later in life and develop a degenerative brain disease called chronic traumatic encephalopathy, or CTE.
When Mr. Fleming died in 2009 at the age of 73, he had dementia. Researchers found the telltale signs of CTE in his brain, including the buildup of a protein that is also implicated in Alzheimer's disease. CTE is a condition that can be diagnosed only with an autopsy, and was first documented in the brains of former boxers.
The Lethbridge team is using epigenetics to learn more about how injuries translate into long-term damage. Epigenetics is a hot area in brain research, one that may yield new insights into many diseases that affect the brain.
"How do you bridge the gap between an event that occurs at age 10 and what happens when you are 65?" Dr. Sutherland said. "One way is epigenetic. Something has altered the expression of genes in a permanent way."
For example, do concussions make some genes, perhaps those involved in brain repair, less active? Over time does that lead to damage that causes memory loss and other problems?
Dr. Sutherland is particular intrigued by the question of whether concussions or other injuries affect a small area in a memory centre of the brain where new brain cells are generated.
"It is a really good spot for an early injury to have a lasting effect," he said.
But this in only one strand of his research. He devotes much of his time to investigating how to get the brain to generate new cells. One day, it might lead to new treatments for people who have suffered from a traumatic brain injury or for cancer patients who have lost brain cells because of chemotherapy or radiation treatments.