Scientists from the University of Lancaster (United Kingdom) and the University Medical Center of Ljubljana (Slovenia) have discovered “apparent changes” in the brains of older people that alter the coordination between neural activity and oxygenation of the brain.
The brain requires up to 20 percent of the body’s energy, so the brain and cardiovascular system have to work together to ensure an adequate supply of energy to each part of the brain. It is in charge of several “neurovascular units” responsible for nourishing the neurons.
Non-invasive recording of the function of these neurovascular units in living humans had never been done before, but has now been achieved using a variety of measurement techniques combined with novel analysis methods developed at Lancaster University.
In the study, published in the scientific journal Brain Research Bulletin, blood oxygenation of live brains was measured with infrared light, which easily penetrates the skull. Neuronal activity in the brain is linked to electrical activity, which was simultaneously measured on the surface of the skull.
The body hums with rhythm, the most famous of which is the heartbeat. Other rhythms include breathing, brain waves, and processes that regulate blood pressure and blood flow by changing the diameter of blood vessels.
Simultaneous measurements of oxygenation, brain electrical activity, respiration and cardiac electrical activity allowed the researchers to capture these rhythms and their imperfect timing. He then studied the strength of these rhythms and their timing, calculating their ‘phase coherence’.
The results showed that the amplitude of oscillations in the cerebral vasculature and brain waves changed in the older age group. But the change in coherence between them is more dramatic, indicating that the timing of energy supply and demand in the brain is negatively affected by age.
The world population is aging and the incidence of dementia is increasing. Therefore, the ability to monitor treatment adherence and disease progression will become increasingly important in the coming years, especially given the prospect of evaluating new drugs against Alzheimer’s.
“Thus, this method can be used to non-invasively assess the decline in neurovascular function in normal aging, as well as monitor the efficacy of treatments or lifestyle changes in a wide range of neurodegenerative disorders.” Can The results promise a relatively simple and non-invasive method for assessing brain status in healthy aging and neurodegenerative disorders such as Alzheimer’s disease”, explained Aneta Stefanowska, one of the people in charge of the research.