Animal Modeling of Early Programming and Disruption of Pubertal Maturation

Puberty is a fascinating developmental transition that gates the attainment of reproductive capacity and culminates the somatic and sexual maturation of the organism. Rather than a circumscribed phenomenon, puberty is the endpoint of a long-lasting developmental continuum, which initiates in utero. Besides important genetic determinants, the tempo of puberty is influenced by numerous endogenous and exogenous factors that, acting at different levels of the developing hypothalamic-pituitary-gonadal (HPG) axis along the maturational continuum indicated above, can influence puberty onset. Among the different modifiers of puberty, in this chapter we will focus our attention on two major groups of signals, sex steroids and nutritional cues, and how these interplay mostly with the central elements of the HPG axis, and especially with gonadotropin-releasing hormone neurons and their key upstream afferents, Kiss1 neurons, to influence the timing of puberty. Special emphasis will be given to summarize information emerging from relevant preclinical (mostly rodent) animal models, and how this information might be relevant in terms of translational medicine, as it may help for a better understanding and eventually management of pubertal disorders of escalating prevalence worldwide.