Aging affects the whole organism, and also the brain loses faculties over time, to which a series of unhealthy habits contribute. However the declive mental starts later than previously thought, specifically when we have between 30 and 40 yearsand not from the age of 25 as previously believed, as discovered by a group of scientists from the Utrecht University Medical Center (UMC Utrecht) and the Mayo Clinic after analyzing the brain processing speed and the changes that occur in this organ as we age.
Rapid communication between neurons in different areas of the brain is key to a correct cognitive function and the results of the study – which have been published in Nature Neuroscience– reveal that the speed of connections in our brain it increases progressively and goes from two meters per second in four-year-old children to four meters per second in adults between 30 and 40 years of age; that is, it doubles and only after that age does it start to slow down. “Our brain continues to develop much more than we thought,” said Dorien van Blooijs, a clinical technologist and one of the paper’s authors.
Researchers have also found differences between brain regions. For example, him frontal lobe, which is responsible for thinking and performing tasks, develops over a longer time than an area responsible for movement, so the development of speed is not a straight line, but a curve. “We already knew this thanks to previous research, but now we have hard data,” Van Blooijs said.
A map of the brain to study brain disorders
To obtain the data, precise measurements were carried out using an electrode grid that is placed under the skull in some patients with epilepsy to prepare for epilepsy surgery, and which consists of 60 to 100 electrodes that can measure the activity cerebral. “By stimulating the electrodes with short currents, we can see which areas of the brain respond abnormally. Therefore, we can create a map of which areas should and should not be removed during epilepsy surgery,” explained neurologist Frans Leijten, another of the authors.
“With our data, researchers can create new and better computer models that further our understanding of the brain”
These data have allowed researchers to learn more about the functioning of the brain, opening up new perspectives. “We’ve been collecting this data for about 20 years,” says Leijten, but “it wasn’t until a few years ago that we realized we could use unaffected areas as model for the healthy human brain”. Van Blooijs adds: “If an electrode is stimulated in one area, a reaction occurs in another. This lets you know that the two areas are connected. Then you can measure how long it takes for the reaction to occur. Knowing the distance between the two different brain regions can calculate how fast the signal is transmitted.”
The findings of this research provide relevant information about our central nervous system. Scientists have been trying to map the connections in our brain for a long time, and thanks to this information, experts can design more realistic computer models of our brain.
For these models to work, in addition to information about the connections, precise values about the speed of those connections are needed. “We now have these numbers for the first time,” explains Leijten, “with our data, researchers can create new and better computer models that further our understanding of the brain. We hope that our work will not only advance epilepsy research, but also research on other brain disorders”.