Are there differences in the brain of a man who feels like a woman, or in that of a woman who feels like a man? To answer this question, researchers from the National Distance Education University (UNED), in collaboration with other centers, have measured the thickness of the cerebral cortex of transsexual people. The results confirm the biological roots of transsexuality.
The study, which is published in the journalCerebral Cortex, included both transsexual men and women who had not undergone hormonal treatment to change their sex, as well as non-transsexual men and women. Using neuroimaging techniques, the researchers found thatthe thickness of the cortex of men who feel like women is different from that of other men, which generally have a thinner crust, and look more like that of women. On the contrary, in the case of females there are no differences, that is, the thickness of this tissue corresponds to their biological sex. However, the volume of one of the subcortical nuclei of their brain is similar to that of the male, indicating thattranssexual women differ in subcortical structures.
“These data indicate that the gray matter of transsexual women and men shows signs of masculinization and feminization, respectively,” points out Antonio Guillamón, one of the study’s authors. The origin of these differences is unknown, but experts point to an asymmetry in the effect of androgens, sex hormones, during brain development in these people.
