The health of blood vessels is essential for brain health and could play a crucial role in addressing age-related cognitive decline and neurodegenerative disorders like Alzheimer’s disease, according to a new study by Penn State researchers published in Nature Communications. The study utilized advanced imaging techniques to develop maps of the mouse brain that illustrate how blood vessels change with age and identified vulnerable areas that could lead to deterioration. When blood vessels degrade, neurons in the brain can become starved of energy, leading to conditions like vascular dementia and symptoms such as sleep disturbances.
The lead author of the study, Yongsoo Kim, emphasized the importance of understanding how cells and structures in the brain change before major issues like cell death occur. This study aims to provide early signs of neurodegenerative disorders, potentially leading to earlier diagnosis and clues on how to slow down the aging process. Aging is a primary factor in neurodegenerative disorders, making it crucial to understand how normal aging affects the brain’s vasculature, especially with the aging population in the United States expanding.
Most existing research focuses on how neuron structure and function degenerates over time rather than the vasculature. The study by Kim and his team used high-resolution 3D mapping techniques to create a detailed map of the vascular network in the mouse brain to chart changes with normal aging. They found that significant changes occur in areas deep in the brain, rather than the regions usually studied, suggesting that previous research may have been examining the wrong areas concerning aging studies. The team found that changes in the vascular network are concentrated in areas like the basal forebrain, deep cortical layers, and hippocampal network.
As brains age, the length and branching density of blood vessels decrease, indicating a sparser network to distribute blood. Arteries in older brains also show more twists, which can impede blood flow, especially to areas further away from the main arteries. The study also found that the vascular system responds more slowly in older brains, making it challenging to provide neurons with energy as quickly as they may need. Additionally, there is a loss of pericytes, a cell type that regulates blood supply and blood vessel permeability, leading to compromised blood-brain barrier integrity.
This study builds on the researchers’ previous work mapping the vasculature of a young mouse brain and aims to further investigate how Alzheimer’s disease-induced changes in the brain influence vascular health and neuronal function. Ultimately, the researchers hope that their findings will lead to the development of treatments for neurodegenerative disorders. The study was co-led by Hannah Bennett, Steffy Manjila, Quingguang Zhang, and Yuan-ting Wu, with contributions from other Penn State researchers. Funding for the study was provided by the National Institutes of Health and the American Heart Association.