Features
Giving the Brain a Boost
Biomedical scientist's research ties hormones to increased synaptic function
BY REBECCA MOORE
SPARK PROGRAM
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| Prof. Neil MacLusky is studying how two common groups of hormones can boost brain function and memory. Photo by Kyle Rodriguez |
Estrogen and androgen, two common groups of hormones, are known for their effects on the human reproductive tract. But Guelph researchers say they may have another function in the human body — in the brain.
Prof. Neil MacLusky, chair of the Department of Biomedical Sciences, says estrogen and androgen may help improve memory and synapse formation (the bridges between nerves that enable movements and responses to occur), warding off diseases such as Alzheimer's, Parkinson's and other forms of dementia.
“It turns out that androgens and estrogens are important to maintaining the health of the brain,” he says, “and they have a huge impact on synapse formation and memory.”
Recent research has found that estrogen and androgen enhance brain function by improving synapse formation in the hippocampus, an area of the human brain that's important for committing experiences to memory. These hormones decrease naturally with age, and this may be a contributing factor to age-related mental degeneration, says MacLusky.
He notes that maintaining mental health is becoming a primary concern for the public health sector. Among his research projects, he is studying the potential of natural estrogen sources to reduce the impact of hormone deficiency-related aging.
His timing couldn't be better. One in 10 people over the age of 65 and nearly half of those aged 85 or older have Alzheimer's disease. The situation represents a potentially serious public health risk as life expectancy continues to rise, says MacLusky.
“With the increasing likelihood of neurological problems as we age, we are potentially looking at a public health nightmare. It would prove to be a terrible burden on families, caregivers and the public health system if we don't find solutions.”
In one project, he and a team of researchers at Toronto's Sunnybrook Health Sciences Centre are studying the impact of using estrogen therapy on aging women who are beginning to show symptoms of Alzheimer's. Early results look promising, and the team hopes to shed light on the potential of hormone therapy to reverse or at least slow some mental degeneration.
Using hormone therapy to tap into the perceived benefits of estrogens and androgens is not simple, says MacLusky. Because most currently used hormone therapies have more than one effect, patients hoping to gain a mental edge may also run the risk of developing cancer and other health consequences. But these problems may be overcome because of the potential for developing more specific hormone therapies, capable of triggering synapse formation in the brain without adverse effects.
The estrogens present in soybeans, the so-called phytoestrogens, represent one possible example. Initially, these estrogens were thought to have minimal impact on the human body because the receptor that allows estrogen to trigger synapse formation was unknown — until now.
MacLusky's research is finding that, at least in animals, low doses of phytoestrogen have a major impact on synapse formation in the brain, without stimulating undesired growth responses elsewhere in the body.
The next step is to identify the exact composition of this hormone receptor. Then it will be easier to determine what hormones may be best suited for brain health, he says.
His research is funded by the Canadian Institutes of Health Research and the U.S. National Institutes of Health.