Androgenic anabolic steroid exposure during adolescence: ramifications for brain development and behavior.

This article is part of a Special Issue "Puberty and Adolescence". Puberty is a critical period for brain maturation that is highly dependent on gonadal sex hormones. Modifications in the gonadal steroid environment, via the use of anabolic androgenic steroids (AAS), have been shown to affect brain development and behavior.

The ethics of neuroscience and the neuroscience of ethics: a phenomenological-existential approach.

Advances in the neurosciences have many implications for a collective understanding of what it means to be human, in particular, notions of the self, the concept of volition or agency, questions of individual responsibility, and the phenomenology of consciousness. As the ability to peer directly into the brain is scientifically honed, and conscious states can be correlated with patterns of neural processing, an easy--but premature--leap is to postulate a one-way, brain-based determinism. That leap is problematic, however, and emerging findings in neuroscience can even be seen as compatible with some of the basic tenets of existentialism.

Androgen receptors, sex behavior, and aggression.

Androgens are intricately involved in reproductive and aggressive behaviors, but the role of the androgen receptor in mediating these behaviors is less defined. Further, activity of the hypothalamic-pituitary-gonadal axis and hypothalamic-pituitary-adrenal axis can influence each other at the level of the androgen receptor. Knowledge of the mechanisms for androgens' effects on behaviors through the androgen receptor will guide future studies in elucidating male reproductive and aggressive behavior repertoires.

Changes in circadian rhythms during puberty in Rattus norvegicus: developmental time course and gonadal dependency.

During puberty, humans develop a later chronotype, exhibiting a phase-delayed daily rest/activity rhythm. The purpose of this study was to determine: 1) whether similar changes in chronotype occur during puberty in a laboratory rodent species, 2) whether these changes are due to pubertal hormones affecting the circadian timekeeping system. We tracked the phasing and distribution of wheel-running activity rhythms during post-weaning development in rats that were gonadectomized before puberty or left intact.

Effects of anabolic androgenic steroids and social subjugation on behavior and neurochemistry in male rats.

Early abuse and anabolic androgenic steroids (AAS) both increase aggression. We assessed the behavioral and neurochemical consequences of AAS, alone or in combination with social subjugation (SS), an animal model of child abuse. On P26, gonadally intact male rats began SS consisting of daily pairings with an adult male for 2 weeks followed by daily injections of the AAS, testosterone on P40.