Puberty in Nonhuman Primates and Humans
2006; Elsevier BV; Linguagem: Inglês
10.1016/b978-012515400-0/50045-2
AutoresTony M. Plant, Selma F. Witchel,
Tópico(s)Regulation of Appetite and Obesity
ResumoThis chapter discusses puberty in humans and nonhuman primates. In primates, as in other mammalian species, the state of having entered the development stage defined as puberty, which in catarrhines may span a time frame of several years, is recognized by the cascade of morphological, physiological, and behavioral sequela of increased gonadal and, in some cases, adrenal activity. Some of these biological changes are relatively discrete and therefore provide quantitative markers of this transitional phase in development. In males, maturation of the neural timing mechanism that governs pulsatile gonadotropin-releasing hormone (GnRH) secretion appears to be completed during fetal development, but in the female the ontogeny of this system may not be completed until after birth. The protracted brake on GnRH secretion from late infancy until puberty that is a developmental hallmark of higher primates is imposed primarily by extragonadal mechanisms. The rising circulating concentrations of sex steroids produced as a result of gonadarche, however, retard the pubertal resurgence in pulsatile GnRH release that, in the absence of gonadal steroids, appears to occur explosively. Thus, the tempo of puberty in humans and nonhuman primates is dictated by interplay of central and gonadal factors.
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