Hormonal treatments administered as part of the procedures for sex reassignment can not only shift a recipient's physical appearance to that of the opposite sex but also alter brain chemistry says a new study. The researchers showed that administration of the male hormone testosterone in female-to-male transsexuals raises brain levels of SERT the protein that transports the chemical messenger serotonin into nerve cells. In contrast male-to-female transsexuals who received a testosterone blocker and the female hormone estrogen showed decreased levels of this protein in the brain. (Read: Testosterone therapy during sex change surgeries makes women think like men) SERT plays
