ARCHIVED - Research About – Alzheimer’s Disease

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The Canadian Institutes of Health Research (CIHR) is the Government of Canada's agency for health research. CIHR's mission is to create new scientific knowledge and to catalyze its translation into improved health, more effective health services and products, and a strengthened Canadian health-care system. Composed of 13 Institutes, CIHR provides leadership and support to more than 13,000 health researchers and trainees across Canada. Through CIHR, the Government of Canada invested approximately $22.1 million in 2008-09 in Alzheimer's disease research.

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The Facts

• Alzheimer's disease, the most common form of dementia, is named for the German physician, Dr. Alois Alzheimer, who first described it in 1906 after treating a woman who had developed memory problems and had difficulty speaking and understanding what was said to her.*
• Of the approximately 500,000 Canadians currently living with Alzheimer's disease or a related dementia, 71,000 are under age 65.**
• Women represent 72% of all cases of Alzheimer's disease. In the context of overall dementia, women represent 62% of cases.**
• In the U.S., Alzheimer's disease is the fifth leading cause of death in persons aged 65 years and older. Between 2000 and 2006, deaths attributable to Alzheimer's disease increased by 47%.***
• A recent survey of caregivers found that more than a third had observed aggression in the person they were caring for with Alzheimer's disease. Almost one quarter (23%) of caregivers had felt scared or threatened by the individual's behaviours.****
• During 2008, unpaid caregivers in the U.S. provided 8.5 billion hours of care for patients with Alzheimer's disease and related dementias, a service valued at $94 billion.***

Sources:

^* The Alzheimer's Association, What is Alzheimer's?

^**  Alzheimer Society of Canada, Highlights of findings in the report Rising Tide: The Impact of Dementia on Canadian Society.

^** 2009 Alzheimer's disease facts and figures, Alzheimer's Association.

^**** Alzheimer's Foundation of Canada, January 2009 Media Release: Caregivers often feel threatened by behaviours of person with Alzheimer's disease.

Finding Solutions

Synthetic molecule may boost neuron function

CIHR-funded researchers have traced the learning and memory deficits associated with Alzheimer's disease to the buildup of a protein called amyloid beta that damages neurons responsive to the neurotransmitter acetylcholine. This neurotransmitter is essential for proper cognitive function. Dr. Isabelle Aubert of the Sunnybrook Health Sciences Centre at the University of Toronto is working on developing a strategy to stop the toxicity of amyloid beta and improve the function of these specific neurons, known as cholinergic neurons. She and her colleagues have shown that a synthetic molecule called C3d can stimulate the synthesis of acetylcholine, findings that were recently published in the Journal of Neuroscience Research. This research could lead to new strategies to stimulate cholinergic function and improve cognition in people with Alzheimer's disease.

Common medication reduces rodents' brain plaque

A drug commonly used to treat epilepsy and bipolar disorder improves memory and reduces brain plaque in mice with Alzheimer's disease, a CIHR-supported study has shown. According to the University of British Columbia's Dr. Weihong Song, mice treated with valproic acid (VPA), a chemical compound used as a mood stabilizer and anti-convulsant, experienced reductions in brain plaque, which led to less cell death and improved scores on memory tests. The Journal of Experimental Medicine published the study's findings.

Missing copy of gene leads to brain tangles in mice

Missing one copy of a gene may put people at greater risk for developing Alzheimer's, Canadian researchers have found. CIHR-supported researcher Dr. David Kaplan, a Canada Research Chair in Cancer and Neuroscience at the University of Toronto, examined mice with only one copy of the p73 gene instead of the normal two. Their brains contained tangles that are believed to disrupt connections between brain cells and are a hallmark of neurodegeneration. About 10% of people have only one copy of the p73 gene. The findings were published in Neuron.

COACHing the way through daily activities
CIHR-funded researcher Dr. Alex Mihailidis of the University of Toronto leads a team that has developed an automated prompting system called COACH (Cognitive Orthosis for Assisting aCtivities in the Home) to track the actions of older adults during daily activities and provide verbal and visual prompts. For example, a "talking bathroom" prototype uses an overhead camera to monitor a person's movements as he or she stands at a sink to wash their hands. When the person hesitates, the camera feeds a message to a computer that offers verbal prompts such as "turn on the tap." The COACH system is designed to help people with dementia perform routine tasks and to ease the stress on caregivers. Results of a study published in BMC Geriatrics showed that use of the COACH system resulted in 60% fewer interactions with caregivers during hand washing.

Report predicts dementia numbers will double
The number of Canadians living with Alzheimer's disease could double over the next 25 years, according to a new study funded in part by CIHR. The Alzheimer Society of Canada report, Rising Tide: The Impact of Dementia on Canadian Society, says 500,000 Canadians currently live with Alzheimer's or other forms of dementia. It predicts that number could grow to more than a million by about 2035. The estimates are based on current rates of dementia per year, statistics of current incidences, dementia rates from other countries, and information from the 1991-2001 Canadian Study on Health and Aging.

The Researchers

Dr. Cheryl Grady - Why Aging Brains Wander

A father of modern science, Rene Descartes, wrote I think, therefore I am. Canadian neuroscientist Dr. Cheryl Grady has a different take on this famous mental maxim: it's how you think that determines who you are—and this, importantly, changes with age.

Dr. Grady's CIHR-funded research is revealing how our brain function differs with age, providing clues to both improving memory and focus in later life and possibly treating cognitive disorders such as Alzheimer's.

"As humans we can always learn. There's never a point due to age where we can't pick up new information," says Dr. Grady, the Canada Research Chair in Neurocognitive Aging at the Rotman Research Institute at the University of Toronto and Baycrest. "What changes is how our brains function with age, and this alters how we perceive our environments and think."

To observe these changes, Dr. Grady uses functional magnetic resonance imaging (fMRI). This medical imaging technique monitors blood flow in the brain as an indicator of localized brain activity.

Through fMRI studies, Dr. Grady has discovered that starting in middle age (ages 40 to 60) our brains literally become more self-absorbed, resulting in what's often experienced as distraction, or lack of focus.

Dr. Grady's discovery comes from comparing the function of two brain networks, what she calls the task-positive network and the default-mode network. The task-positive network is active when we perform a mental task, such as learning a list of words. The default mode is the internal audio-stream of thoughts that often occupies our minds: memories; to-do lists; self-reflections.

"In all of us there's a see-saw motion of activity between these two brain networks," says Dr. Grady. "But what we've found is that as we age, we don't turn down the default mode as much as younger adults do. It's harder to turn off this internal thought process."

The results, she says, explain why older people find it harder to concentrate, and why minimizing external distractions can improve focus.

This brain network switching could also provide clues as to how our brains cope with the initial changes brought on by Alzheimer's. Dr. Grady's research has found that in patients with early stage Alzheimer's, memory is improved when there's compensatory activity in usually non-related brain networks.

Now she's on the trail to understand what triggers our wandering minds.

"What is the switch that causes this see-saw between the task and default mode networks?" says Dr. Grady. "At a fundamental level we need to understand what the mechanism is for our brains to go from one network to the other, and to ask is this what changes with age?"

For More Information

CIHR's Institute of Aging (CIHR-IA) has identified five themes as urgent research priorities for Canada: cognitive impairment in aging, mobility and functional autonomy, healthy aging, health services for an aging population, and the biological processes of aging itself. As the stories above demonstrate, the impact of early investments and strategic development in these research domains is now evident. To learn more about these priorities and other CIHR-IA activities, please visit the Institute's website.

For more information, go to ARCHIVED - Your Health Research Dollars at Work