Author/Editor		Kranz, Georg S.; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, René E.; Winkler, Dietmar; Swaab, Dick Frans; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert
Title		White matter microstructure in transsexuals and controls investigated by diffusion tensor imaging
Type		članek
Vol. and No.		Letnik 34, št. 46
Publication year		2014
Volume		str. 15466-15475
ISSN		0270-6474 - The Journal of neuroscience : the official journal of the Society for Neuroscience
Language		eng
Abstract		Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increasedattention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white mattermicrostructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, andsexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI).Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwentDTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fibertractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs hadhighest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowestvalues. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No signifi-cantdifferencesinfractionalanisotropymapswerefoundbetweengroups.Plasmatestosteronelevelswerestronglycorrelatedwithmean,axial,and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects' sexual orien-tation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonalenvironment during late prenatal and early postnatal brain development
Keywords		testosterone gender identity disorder diffusion tensor imaging testosteron motnje spolne identitete upodabljanje difuzijskega tenzorja