Mouse MRI shows brain areas relatively larger in males emerge before those larger in females

• Published in: Nature communications Vol. 9; no. 1; pp. 2615 - 15
• Main Authors: Qiu, Lily R., Fernandes, Darren J., Szulc-Lerch, Kamila U., Dazai, Jun, Nieman, Brian J., Turnbull, Daniel H., Foster, Jane A., Palmert, Mark R., Lerch, Jason P.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.07.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 59; 59/57; 631/378/2571/1696; 631/378/3920; Anatomy; Animals; Animals, Newborn; Brain; Brain - anatomy & histology; Brain - growth & development; Brain architecture; Disorders; Female; Females; Gender aspects; Gender differences; Gene expression; Humanities and Social Sciences; Image enhancement; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Males; Manganese; Manganese - chemistry; Mental disorders; Mice, Inbred C57BL; multidisciplinary; Neuroanatomy - methods; Science; Science (multidisciplinary); Sex; Sex differences; Sex Factors; Sexual behavior; Sexual dimorphism; Time Factors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04921-2

Sex differences exist in behaviors, disease and neuropsychiatric disorders. Sexual dimorphisms however, have yet to be studied across the whole brain and across a comprehensive time course of postnatal development. Here, we use manganese-enhanced MRI (MEMRI) to longitudinally image male and female C57BL/6J mice across 9 time points, beginning at postnatal day 3. We recapitulate findings on canonically dimorphic areas, demonstrating MEMRI’s ability to study neuroanatomical sex differences. We discover, upon whole-brain volume correction, that neuroanatomical regions larger in males develop earlier than those larger in females. Groups of areas with shared sexually dimorphic developmental trajectories reflect behavioral and functional networks, and expression of genes involved with sex processes. Also, post-pubertal neuroanatomy is highly individualized, and individualization occurs earlier in males. Our results demonstrate the ability of MEMRI to reveal comprehensive developmental differences between male and female brains, which will improve our understanding of sex-specific predispositions to various neuropsychiatric disorders. Sex differences occur in various aspects of neurodevelopment. Here the authors use manganese-enhanced MRI at nine different postnatal stages to detail the development of structural sex differences in the mouse brain.