Format

Send to

Choose Destination
See comment in PubMed Commons below
J Neurosci. 2008 Sep 17;28(38):9519-24. doi: 10.1523/JNEUROSCI.1212-08.2008.

Growth of white matter in the adolescent brain: role of testosterone and androgen receptor.

Author information

1
Brain and Body Centre, University of Nottingham, Nottingham NG72RD, United Kingdom.

Abstract

The growth of white matter during human adolescence shows a striking sexual dimorphism; the volume of white matter increases with age slightly in girls and steeply in boys. Here, we provide evidence supporting the role of androgen receptor (AR) in mediating the effect of testosterone on white matter. In a large sample of typically developing adolescents (n = 408, 204 males), we used magnetic resonance imaging and acquired T1-weighted and magnetization transfer ratio (MTR) images. We also measured plasma levels of testosterone and genotyped a functional polymorphism in the AR gene, namely the number of CAG repeats in exon 1 believed to be inversely proportional to the AR transcriptional activity. We found that the testosterone-related increase of white-matter volume was stronger in male adolescents with the lower versus higher number of CAG repeats in the AR gene, with testosterone explaining, respectively, 26 and 8% of variance in the volume. The MTR results suggest that this growth is not related to myelination; the MTR decreased with age in male adolescents. We speculate that testosterone affects axonal caliber rather than the thickness of the myelin sheath.

PMID:
18799683
DOI:
10.1523/JNEUROSCI.1212-08.2008
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center