Regional sex differences in grey matter volume are associated with sex hormones in the young adult human brain.
Previous studies suggest organizing effects of sex hormones on brain structure during early life and puberty, yet little is known about the adult period. The aim of the present study was to elucidate the role of 17beta-estradiol, progesterone, and testosterone on cortical sex differences in grey matter volume (GM) of the adult human brain. To assess sexual dimorphism, voxel-based morphometry (VBM) was applied on structural magnetic resonance images of 34 healthy, young adult humans (17 women, 17 men, 26.6+/-5 years) using analyses of covariance. Subsequently, circulating levels of sex hormones were associated with regional GM using linear regression analyses. After adjustment for sex and total GM, significant associations of regional GM and 17beta-estradiol were observed in the left inferior frontal gyrus (beta=0.39, p=0.02). Regional GM was inversely associated with testosterone in the left inferior frontal gyrus (beta=-0.16, p=0.04), and with progesterone in the right temporal pole (beta=-0.39, p=0.008). Our findings indicate that even in young adulthood, sex hormones exert organizing effects on regional GM. This might help to shed further light on the underlying mechanisms of both functional diversities and congruence between female and male brains.
Witte
A Veronica
AV
Department of Psychiatry, Functional NeuroImaging Unit - PET & fMRI, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Savli
Markus
M
Holik
Alexander
A
Kasper
Siegfried
S
Lanzenberger
Rupert
R
D000328:Adult; D000375:Aging; D000704:Analysis of Variance; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D005260:Female; D042341:Gonadal Hormones / Q000097:blood*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D036421:Nerve Fibers, Unmyelinated; D009929:Organ Size; D011374:Progesterone / Q000097:blood; D012727:Sex Characteristics; D013739:Testosterone / Q000097:blood
D042341:Gonadal Hormones; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol