title: Puberty and testosterone shape the corticospinal tract during male adolescence.
abstract: Some of the known sex differences in white matter emerge during adolescence. Here, we replicate and extend our previous findings of sex differences in the structure of the corticospinal tract (Perrin et al. 2009; Hervé et al. 2009). In a large normative sample of adolescents, we observed age × sex interactions in the signal intensity of T1-weighted (T1W) images (n = 941) and in magnetization transfer ratio (MTR; n = 761); both features were inversely associated with age in males but not in females. Moreover, we hypothesized that the age-related differences in CST structure exhibited by males would be mediated by differences in puberty stage and levels of bioavailable testosterone. We confirmed this prediction using mediation analysis with bootstrapping. These findings suggest that sex differences in the CST structure observed during male adolescence may be due to multiple processes associated with puberty, including (but not limited to) the rising levels of testosterone.
authors.affiliation: Rotman Research Institute, Baycrest Centre for Geriatric Care, 3560 Bathurst Street, Toronto, ON, M6A 2E1, Canada.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Pangelinan
authors.affiliation: Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Leonard
authors.affiliation: ECOBES, Céjep de Jonquière, 2505 Rue Saint Hubert, Jonquière, QC, G7X 3W1, Canada.|Département des Sciences de la Santé, Université du Québec à Chicoutimi, 555 Boulevard de l'Université, Chicoutimi, QC, G7H 2B1, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Perron
authors.affiliation: Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Pike
authors.affiliation: Département des Sciences de la Santé, Université du Québec à Chicoutimi, 555 Boulevard de l'Université, Chicoutimi, QC, G7H 2B1, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Richer
authors.affiliation: ECOBES, Céjep de Jonquière, 2505 Rue Saint Hubert, Jonquière, QC, G7X 3W1, Canada.|Département des Sciences de la Santé, Université du Québec à Chicoutimi, 555 Boulevard de l'Université, Chicoutimi, QC, G7H 2B1, Canada.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Veillette
authors.affiliation: The Hospital of Sick Children, Toronto, ON, M5G 1X8, Canada.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Pausova
authors.affiliation: Rotman Research Institute, Baycrest Centre for Geriatric Care, 3560 Bathurst Street, Toronto, ON, M6A 2E1, Canada. tpaus@research.baycrest.org.|Departments of Psychology and Psychiatry, University of Toronto, 100 St. George Street, Toronto, ON, M5S 3G3, Canada. tpaus@research.baycrest.org.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Paus
mesh_terms: D000293:Adolescent; D001921:Brain / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011627:Puberty / Q000502:physiology*; D011712:Pyramidal Tracts / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012727:Sex Characteristics; D012737:Sex Factors; D012741:Sexual Maturation; D013739:Testosterone / Q000378:metabolism / Q000502:physiology*; D066127:White Matter / Q000502:physiology
chemical_list: D013739:Testosterone
keywords: Development; MRI; Magnetization transfer; White matter