Endocrine Changes in Puberty

In humans, puberty is defined as the interval between first signs of disinhibition of the central neuroendocrine systems controlling pituitary-gonadal function and the completion of sexual development and achievement of reproductive competence. The morphologic correlates of puberty include rapid physical growth (the adolescent “growth spurt”) and development of secondary sexual characteristics. These, in turn, are the result of the interdependent maturation of several endocrine systems, most prominently the secretion of sex steroids from the gonads.

Less well defined are the psychological and behavioral changes that accompany puberty. Alterations in sleep-wake behavior, while prominent, remain unexplained and may reflect a complex interaction between social changes in the pubertal child's environment and the changing internal neuroendocrine milieu. Neurophysiologic changes also occur during puberty, some of which appear to be steroid-dependent. The wide distribution throughout the brain of specific steroid receptors suggests a mechanism to correlate neurological, psychological, and behavioral changes; however, not all changes in structure and function of the nervous system during the pubertal transition are consequences of changing influences. While sex steroids have important effects on nervous system development, both during the initial prenatal exposure and during puberty, other maturational events are independent of sex steroids (Ojeda, 1991).

Animal models of puberty are clearly necessary to a systematic exploration of the physiology of the process of sexual maturation. Current models are characterized using definitions of analogous changes in sexual morphology and endocrine markers.