Sex steroids and brain structure in pubertal boys and girls

Peper, Jiska S.; Brouwer, Rachel M.; Schnack, Hugo G.; van Baal, G. Caroline; van Leeuwen, Marieke; van den Berg, Stéphanie M.; Delemarre-Van de Waal, Henriëtte A.; Boomsma, Dorret I.; Kahn, René S.; Hulshoff Pol, Hilleke E.

doi:10.1016/j.psyneuen.2008.09.012

« Previous Next »Psychoneuroendocrinology
Volume 34, Issue 3 , Pages 332-342, April 2009

Sex steroids and brain structure in pubertal boys and girls

Jiska S. Peper
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands
- Corresponding author at: University Medical Center Utrecht, Heidelberglaan 100, A01.126, 3584 CX Utrecht, The Netherlands. Tel.: +31 88 755 3379; fax: +31 88 755 5443.
Rachel M. Brouwer
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands
Hugo G. Schnack
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands
G. Caroline van Baal
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands
Marieke van Leeuwen
- Department of Biological Psychology, VU University, Amsterdam, The Netherlands
Stéphanie M. van den Berg
- Department of Biological Psychology, VU University, Amsterdam, The Netherlands
- Current address: Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Henriëtte A. Delemarre-Van de Waal
- Pediatric Endocrinology, VU Medical Center, Amsterdam, The Netherlands
Dorret I. Boomsma
- Department of Biological Psychology, VU University, Amsterdam, The Netherlands
René S. Kahn
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands
Hilleke E. Hulshoff Pol
- Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center, Utrecht, The Netherlands

Received 28 July 2008; received in revised form 16 September 2008; accepted 21 September 2008.

Summary

Sex steroids exert important organizational effects on brain structure. Early in life, they are involved in brain sexual differentiation. During puberty, sex steroid levels increase considerably. However, to which extent sex steroid production is involved in structural brain development during human puberty remains unknown. The relationship between pubertal rises in testosterone and estradiol levels and brain structure was assessed in 37 boys and 41 girls (10–15 years). Global brain volumes were measured using volumetric-MRI. Regional gray and white matter were quantified with voxel-based morphometry (VBM), a technique which measures relative concentrations (‘density’) of gray and white matter after individual global differences in size and shape of brains have been removed.

Results showed that, corrected for age, global gray matter volume was negatively associated with estradiol levels in girls, and positively with testosterone levels in boys. Regionally, a higher estradiol level in girls was associated with decreases within prefrontal, parietal and middle temporal areas (corrected for age), and with increases in middle frontal-, inferior temporal- and middle occipital gyri. In boys, estradiol and testosterone levels were not related to regional brain structures, nor were testosterone levels in girls. Pubertal sex steroid levels could not explain regional sex differences in regional gray matter density. Boys were significantly younger than girls, which may explain part of the results.

In conclusion, in girls, with the progression of puberty, gray matter development is at least in part directly associated with increased levels of estradiol, whereas in boys, who are in a less advanced pubertal stage, such steroid-related development could not (yet) be found. We suggest that in pubertal girls, estradiol may be implicated in neuronal changes in the cerebral cortex during this important period of brain development.

Keywords: Brain structure, Estradiol, MRI, Puberty, Sex differences, Testosterone