A new study published in the journal Science has shown that biological differences between men and women are reflected at the level of gene activity in various regions of the brain and may be linked to differing susceptibilities to neurological and psychiatric disorders.

The research is based on a high-precision analysis of more than one million cell nuclei obtained from six regions of the cerebral cortex from 30 donors. Scientists used single-cell RNA sequencing, a method that makes it possible to determine which genes are active in individual cell types and how their activity differs between men and women.

The study was conducted with the participation of specialists from the U.S. National Institute of Mental Health and the U.S. National Institute on Aging, who created a detailed map of differences in genetic activity in the brain.

The analysis identified more than 3,000 genes showing differences in expression levels between male and female brains. These differences are not evenly distributed: they depend on specific brain regions and cell types, including neurons and glial cells.

Researchers note that some of these genes overlap with those previously associated with conditions such as Alzheimer’s disease, schizophrenia, attention deficit hyperactivity disorder (ADHD), and mood disorders. This may partly explain why certain brain disorders are more common in men or women.

At the same time, the scientists emphasize that although these differences exist, they are relatively subtle and do not define fundamental distinctions between male and female brains. However, they may influence how disease risks develop and how the body responds to them.

The researchers also point out that a significant portion of these differences may be regulated by sex hormones and genes located on sex chromosomes, although the exact mechanisms remain the subject of further study.

The authors stress that these findings are important for the development of personalized medicine, as taking biological sex into account could improve the accuracy of diagnosis and treatment of brain disorders.