By Kuhl, Nick on November 23, 2019.
Thanks to two funding grants, researchers at the University of Lethbridge will delve further into the basic markers associated with the development of Alzheimer’s disease (AD).
Dr. Majid Mohajerani, principal investigator, and co-investigators, Dr. Robert Sutherland and Dr. Bryan Kolb from the Canadian Centre for Behavioural Neuroscience (CCBN) at the University of Lethbridge, and Dr. David Westaway from the University of Alberta, will primarily use mouse models to understand the underlying biological processes associated with the development of AD, the U of L said in a news release this week.
Their research will examine the links between noise stress and cognitive decline, as well as study the brain correlates of spatial navigation changes in early cognitive impairment and AD, thanks to almost $300,000 in funding for two projects from the Alzheimer Society of Alberta and Northwest Territories and the Alberta Prion Research Institute.
Two abnormal proteins called plaques and tangles are prime suspects in damaging and killing nerve cells in AD. Both are fragments of proteins that get misfolded in AD, but researchers are still unclear where in the brain plaques and tangles emerge and how they contribute to changing the properties of neuronal circuits in the brain and lead to the progression of cognitive impairments.
In the first funded project, Mohajerani, Sutherland and Westaway will investigate these questions to figure out what neural circuits are responsible for spatial navigation deficits in AD, one of its earliest symptoms. These deficits are evident when people lose their way in familiar and unfamiliar places, get lost while driving or wander away from home.
“It is important to understand these primary brain alterations as they provide a target for early-stage therapeutic interventions before the occurrence of significant and irreversible brain damage,” says Sutherland in the release.
The goal of the second project is to explore the effect of traffic noise on general brain learning and plasticity, cognitive functions and its impact on AD neurobehavioural symptoms. A deeper understanding of these harmful environmental exposures, as modifiable risk factors of AD, contributes to improvements in public health.
Recent research publications by Mohajerani, Kolb and post-doctoral fellow Dr. Zahra Jafari showed an association between long-term traffic noise exposure and cognitive decline in healthy animals. In their studies on transgenic mice which develop various aspects of AD, animals were exposed to real traffic noise at a level similar to a typical urban area. The offspring of these mice developed impairments in learning, memory and cognitive performance and earlier aggregation of amyloid-beta plaques, which are precursors of AD.
“Our findings raise questions around the neural mechanisms related to the early development of AD due to traffic noise,” says Kolb in the release. “Further exploration in other animal models is needed, as is looking at the adverse impacts of air pollution, which has been linked to cognitive decline and dementia in humans.”
According to the Alzheimer Society of Canada, more than half a million people were living with dementia in Canada in 2018. With about 25,000 new cases diagnosed every year, the number of people with dementia is expected to rise to around a million people by 2031.
Possible or established risk factors for cognitive impairment include age, family history, genes, diabetes, hearing loss, hypertension, and lifestyle factors such as smoking and alcohol consumption.