In this project, Dr Nicolas Michalski at the Institut Pasteur, France, explores whether blood circulation may be related to the link between hearing loss and dementia.
Project start date: September 2020
Project end date: August 2023
About the project
Social isolation and hearing loss have been identified as risk factors of dementia. People with age-related hearing loss are more likely to develop dementia than people without, and the likelihood increases with hearing loss severity. However, we know very little about the biological processes that link hearing loss and dementia.
Nerve cells, such as those nerve cells within the brain which process sound information, require a continuous supply of oxygen and nutrients to remain healthy. The blood circulatory system is a crucial factor in diseases which affect nerve cell survival in the brain, including dementia. However, we don’t know if the circulatory system is involved in its link with hearing loss.
A better understanding of these processes could help us to determine whether managing hearing loss could prevent or delay the onset and progression of dementia.
How it works
In this project, the researchers will test the idea that hearing loss makes dementia worse by its effects on blood circulation in the brain. They’ll study mouse models of different types of hearing loss and use new brain imaging methods to investigate the patterns of blood vessels in the brains of these mice.
They’ll look at:
- The impact of different types of hearing loss on the circulatory system in the brain
- Whether any changes in the circulatory system in the brain as a result of hearing loss lead to abnormal increases in the levels of typical biological markers of dementia
- And whether restoring hearing to deaf mice can prevent these changes to the circulatory system in the long term, and, as a result, prevent damage to nerve cells.
How will this research benefit people at risk of hearing loss or dementia?
If hearing loss impacts the blood circulatory system in the brain, then it might be possible to use existing drugs that are known to boost or protect blood circulation in the brain to reverse these changes, or to develop appropriate new drugs.
This work could also provide a scientific basis to measure the potential benefits of hearing rehabilitation, through the use of hearing aids in particular, in decreasing the risk of dementia in people with hearing loss. This could lead to changes in health policies to favour systematic screening for hearing loss in the general population and the wider use of hearing aids.
What we’ve learned so far
About the researcher
Dr Nicolas Michalski is a researcher at the Institut Pasteur, France. He was awarded an RNID Discovery Research Grant for this project in 2020, co-funded in partnership with Alzheimer’s Research UK.
Peripheral deafness may be associated with auditory brain dysfunctions and may extend well beyond auditory regions themselves. Our laboratory investigates the diversity, causes and the mechanisms underlying these central dysfunctions, the ways in which they could impede the expected benefits of hearing rehabilitation, and how these problems could be remedied.”
