The role of pubertal hormones in the development of gender identity: fMRI studies

Abstract

The present study is the first to demonstrate that sex differences in hypothalamic activation upon smelling the chemo-signal androstadienone are not acquired during sexual maturation, under the influence of gonadal hormones during puberty, but might be considered hard-wired responses, which already can be observed in prepubertal children. Moreover, the current study is the first to explore sex-atypical hypothalamic responses to androstadienone in male and female individuals with GD at two different developmental stages. Our results suggest that individuals with GD possess certain functional brain characteristics of their experienced gender and might have undergone atypical neuronal sexual differentiation, most likely during early brain development and not during puberty. Additional analyses in other functional (e.g., mental rotation, emotional face matching, resting state data) and structural (e.g., gray and white matter volumes or diffusion tensor imaging data) MRI measures, which are in preparation, should corroborate the present preliminary findings.