The brain takes hits as the arteries get older

Researchers in Umeå, Sweden, presented a model that explains why memory deteriorates as the body ages. With aging, the brain receives an increased load because of the heartbeat because the large arteries of the body stiffen over the years, damaging the smallest blood vessels in the brain.

Lars Nyberg is Professor of Neuroscience and Director of the Umeå Center for Functional Brain Imaging (UFBI). He is a member of the Royal Swedish Academy of Sciences. Credit: Mattias Pettersson

The fact that human memory deteriorates with age increases is what most people sooner or later feel, even among those who avoid diseases such as Alzheimer. Similarly, a relationship between aging of the brain and the body is well known. However, the exact nature of this association is not known.

"We suggest a series of events on the relationship between aging brain and vessels," said Lars Nyberg, a professor at Umeå University.

Umeå researchers, Lars Nyberg and Anders Wåhlin, have created an explanatory model that begins with the heartbeat and crosses the largest arteries of the body to the finest brain vessels. An important feature of the model is that it explains why certain cognitive processes may be particularly at risk for the proposed mechanism.

Anders Wåhlin, researcher in the Department of Radiation Sciences of Umeå University. Credit: University of Umeå

As the human body ages, large arteries, such as the aorta, stiffen and lose much of their ability to absorb the increased pressure generated by the heart ejecting blood. in the arteries. Such pulsatility of pressure is rather transmitted to smaller blood vessels, for example those of the brain. The smallest blood vessels in the brain, the capillaries, are subject to increased stress that damages cells inside and around the walls of the capillaries. These cells play an important role in the regulation of capillary blood flow. If the smaller blood vessels are damaged, it hurts the ability to increase blood supply to the brain during demanding cognitive processes.

According to the researchers' model, the cerebral hippocampus is particularly vulnerable. The structure of this part of the brain is important for episodic memory, that is, the ability to remember past events. The vulnerability of the hippocampus is due to the fact that it is close to large vessels and is thus exposed to the increased load at the beginning of the chain. In a young and healthy person, the pulsations are mild, but in an aging person they can be so powerful that they affect the brain tissue and can damage the blood flow of memory processes.

The Umeå research model is based on a number of previous studies over the last five years.

"We have thrown the current and verified research puzzle into different areas to give a broader and more detailed picture of the course of events. It will be a starting point for future research to better understand and, in the long run, researchers can also find ways to slow down the process, "says Anders Wåhlin.

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The model of Umeå researchers, At the heart of cognitive functioning in aging, has been published in the scientific journal Trends in cognitive science.