New Study Shows Molecular Changes in Aging Brains Occur in White Matter
A recent study conducted on mice has shed light on the significant molecular changes that occur in the white matter of aging brains. The white matter, which is responsible for transmitting brain signals, undergoes the most pronounced changes as the animals age. The study also explored two treatments that could potentially slow age-related cognitive decline.
As individuals reach middle age, many experience a decline in memory and cognitive abilities. However, the precise molecular changes in the brain that cause this decline have not been fully understood by scientists. This recent study on mice has provided new insights into these changes, particularly in the white matter of the brain.
The research team examined 15 regions in the brains of 59 female and male mice aged 3 to 27 months. They identified and ranked the top genes expressed in each region of the brain. The team identified 82 genes that were frequently found and varied in concentration across multiple regions.
According to the study, the white matter showed the earliest and most significant changes in gene expression for mice aged 12 and 18 months, which is equivalent to individuals in their 50s. These changes in gene expression affect the integrity of the myelin sheath, the insulation layer around nerves that facilitates the transmission of signals across the brain.
Dr. Tony Wyss-Coray, a professor of neurology and neurological sciences who led the study, emphasized the importance of white matter in connecting different brain regions together. While the study did not directly establish how these gene expression changes affect memory and cognition, it provides a foundation for further research on the topic.
The study also explored two interventions to slow the decline in specific regions of the brain. One intervention involved caloric restriction, while the other involved infusions of plasma from young mice. Both interventions showed distinct effects on different regions of the brain, suggesting the potential for multiple pathways to improve cognitive performance in old age.
Additionally, the study examined age-related changes in genes associated with neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases, as well as multiple sclerosis. The expression distribution for these genes changed in older mice and occurred in regions of the brain typically not associated with a specific neurodegenerative condition. This finding could provide insights into patients who have neurodegenerative diseases without a known genetic link.
The research team hopes to use the gene expression data to identify cell populations vulnerable to aging and explore treatments and interventions. They also aim to expand their research by building genetic atlases of aging in the human brain.
While the individual gene changes observed in mice may not directly translate to humans, the vulnerability of white matter to aging is believed to hold true. This study opens up new opportunities for understanding normal aging and developing potential treatments for neurodegenerative diseases.
The study received funding from various sources, including the Phil and Penny Knight Initiative for Brain Resilience, the European Research Council, and the Michael J. Fox Foundation for Parkinson’s Research, among others.
The findings of this study have been published in the journal Cell. Researchers from various institutions, including New York University Langone Health and University College London, contributed to the study.