For the first time, American neurophysiologists tracked changes in the structure of the brains of boys and girls as they grew up, which allowed them to reveal significant sex differences in the nature of development and in the structure of connections in their brains, as well as to confirm the conventional wisdom that the nervous system of girls develops faster. The scientists’ findings were published in an article in the journal JAMA Network Open.
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“We uncovered significant differences in how the brains of boys and girls develop from the age of ten. In particular, girls have a higher density of connections between neurons in key nodes of the brain’s passive mode network inside the posterior cingulate cortex, as well as more high density of white matter between the cortex and the striatum of the brain,” the study says.
Many biologists believe that the structure and operation of the brains of men and women are very different due to several evolutionary reasons. In particular, seven years ago, American scientists showed that some parts of the brain in men exchange signals differently than similar regions of the nervous system in women do, and later they found that their brains react differently to pain.
A group of American neuroscientists led by Nora Volkoff, director of the National Institute for the Study of Drug Addiction in Bethesda (USA), conducted the first large-scale study on how the structure of the brain of boys and girls changes as they grow up.
Results of the study and observations
As part of these observations, 8.9 thousand children aged 9-10 years old participated, whose parents agreed to periodic examinations of the state of the brain of their sons and daughters using magnetic resonance imaging. During these measurements, scientists tracked how the structure of the white and gray matter of the brain changes as children grow up, and also compared sets of the most frequent age-related changes in the structure of the nervous system in representatives of different sexes.
Subsequent analysis of these data showed that the developmental trajectories of the brain of girls and boys are very different, and he also pointed out the fundamentally different nature of the formation of connections between different regions of their brain. In particular, scientists have identified large differences in the structure and speed of maturation of the so-called network of the passive mode of the brain, a special chain of interacting regions of the central nervous system, which is active when a person is inactive.
As a rule, girls were characterized by a higher density of connections between neurons in this network, as well as an increased density of white matter in the regions of the brain associated with it. According to Volkov and her colleagues, this reflects the fact that the brain of girls and girls, on average, matures faster than the nervous system of boys and boys does. Scientists have identified similar patterns when comparing the degree of “maturity” of the brain and the level of intellectual development of children.
The discovery of these differences in the nature of brain development in girls and boys, according to Volkov and her colleagues, explains the existence of age-related differences in the cognitive abilities of schoolchildren and schoolgirls. Further observation of the development of the brain of children and adolescents will help to understand when these differences are laid down and how they arise, the neuroscientists concluded.