Influence of sex steroid hormones on the adolescent brain and behavior: An  update

Pilar Vigil; Juan Pablo Del Río; BÁrbara Carrera; Florencia C ArÁnguiz; Hernán Rioseco; Manuel E Cortés

doi:10.1080/00243639.2016.1211863

Influence of sex steroid hormones on the adolescent brain and behavior: An update

Vigil P, Del Río JP, Carrera B, ArÁnguiz FC, Rioseco H, Cortés ME

Published August 2016 The Linacre Quarterly, 83(3), 308-329

DOI 10.1080/00243639.2016.1211863 PMID 27833209 PMC PMC5102198

RRM Academy Synopsis

Sex steroids reshape adolescent brain circuits, a review argues

A review argues that sex hormones reshape the teenage brain, and that this shapes adult behavior. The authors draw on animal and human studies. They also suggest that hormonal contraceptives in the teen years could change that process.

Key Findings

The authors describe a plasticity window in adolescence when organizational brain changes occur through five mechanisms: myelination, neuronal pruning, apoptosis, dendritic spine remodeling, and epigenetic changes.
In 126 adolescents aged 10 to 14 scanned twice, two years apart, brain volume in some regions varied with testosterone and estradiol levels, regardless of age (Herting et al. 2014).
Among 949 individuals, brain connectivity differed by sex: higher connection within each hemisphere in men and between hemispheres in women (Ingalhalikar et al. 2014).
Male hamsters given testosterone before puberty did not copulate. Adult males castrated after puberty responded immediately once given testosterone, which suggests an organizational step during puberty.
Young women using hormonal contraceptives had larger prefrontal cortices (Pletzer et al. 2010) and altered emotional memory (Nielsen et al. 2011) compared with women who were not using them.

Interpretation

This is a literature review of animal and human research. The authors conclude that sex steroids cause lasting changes in the teen brain. They say hormonal contraceptives used in the teen years probably cause changes of their own. The authors note that knowledge of sex steroid effects on behavior is still limited. The findings support larger, longer studies of hormonal contraceptives used in the teen years.

RRM Context

Restorative Reproductive Medicine treats the cycle as a vital sign. The teen years are when that cycle sets up. The authors say hormonal contraceptives, a suppressive medication, probably cause lasting changes in the teen brain. Restorative care for teens with painful or irregular cycles starts by looking for the cause.

Our editorial summary of this paper, not the article's abstract.

Abstract

This review explains the main effects exerted by sex steroids and other hormones on the adolescent brain. During the transition from puberty to adolescence, these hormones participate in the organizational phenomena that structurally shape some brain circuits. In adulthood, this will propitiate some specific behavior as responses to the hormones now activating those neural circuits. Adolescence is, then, a critical "organizational window" for the brain to develop adequately, since steroid hormones perform important functions at this stage. For this reason, the adolescent years are very important for future behaviors in human beings. Changes that occur or fail to occur during adolescence will determine behaviors for the rest of one's lifetime. Consequently, understanding the link between adolescent behavior and brain development as influenced by sex steroids and other hormones and compounds is very important in order to interpret various psycho-affective pathologies.

Lay Summary

The effect of steroid hormones on the development of the adolescent brain, and therefore, on adolescent behavior, is noticeable. This review presents their main activational and organizational effects. During the transition from puberty to adolescence, organizational phenomena triggered by steroids structurally affect the remodeling of brain circuits. Later in adulthood, these changes will be reflected in behavioral responses to such hormones. Adolescence can then be seen as a fundamental "organizational window" during which sex steroids and other hormones and compounds play relevant roles. The understanding of the relationship between adolescent behavior and the way hormones influence brain development help understand some psychological disorders.

Pilar Vigil, Juan Pablo Del Río, Florencia C ArÁnguiz, Hernán Rioseco, Manuel E Cortés

P Vigil, J Río, F ArÁnguiz, H Rioseco, M Cortés

PMID 27833209 27833209 DOI 10.1080/00243639.2016.1211863 10.1080/00243639.2016.1211863 Vigil et al. 2016, Vigil 2016