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Clinical Obstetrics and Gynecology Sep 2020Onset of puberty, as defined by breast stage 2, appears to be starting at younger ages since the 1940s. There is an ongoing controversy regarding what is normative, as... (Review)
Review
Onset of puberty, as defined by breast stage 2, appears to be starting at younger ages since the 1940s. There is an ongoing controversy regarding what is normative, as well as what is normal, and the evaluation that is deemed necessary for girls maturing before 8 years of age. There are potential implications of earlier pubertal timing, including psychosocial consequences during adolescence, as well as longer term risks, such as breast cancer and cardiometabolic risks. There are additional consequences derived from slower pubertal tempo, for age of menarche has not decreased as much as age of breast development; these include longer interval between sexual initiation and intentional childbearing, as well as a broadened window of susceptibility to endocrine-related cancers.
Topics: Adolescent; Adolescent Development; Body Mass Index; Breast; Breast Neoplasms; Cardiometabolic Risk Factors; Child; Female; Humans; Menarche; Psychology; Puberty; Puberty, Precocious; Sexual Maturation
PubMed: 32482957
DOI: 10.1097/GRF.0000000000000537 -
Brain Research Jan 2017Postnatal brain development is studded with sensitive periods during which experience dependent plasticity is enhanced. This enables rapid learning from environmental... (Review)
Review
Postnatal brain development is studded with sensitive periods during which experience dependent plasticity is enhanced. This enables rapid learning from environmental inputs and reorganization of cortical circuits that matches behavior with environmental contingencies. Significant headway has been achieved in characterizing and understanding sensitive period biology in primary sensory cortices, but relatively little is known about sensitive period biology in associative neocortex. One possible mediator is the onset of puberty, which marks the transition to adolescence, when animals shift their behavior toward gaining independence and exploring their social world. Puberty onset correlates with reduced behavioral plasticity in some domains and enhanced plasticity in others, and therefore may drive the transition from juvenile to adolescent brain function. Pubertal onset is also occurring earlier in developed nations, particularly in unserved populations, and earlier puberty is associated with vulnerability for substance use, depression and anxiety. In the present article we review the evidence that supports a causal role for puberty in developmental changes in the function and neurobiology of the associative neocortex. We also propose a model for how pubertal hormones may regulate sensitive period plasticity in associative neocortex. We conclude that the evidence suggests puberty onset may play a causal role in some aspects of associative neocortical development, but that further research that manipulates puberty and measures gonadal hormones is required. We argue that further work of this kind is urgently needed to determine how earlier puberty may negatively impact human health and learning potential. This article is part of a Special Issue entitled SI: Adolescent plasticity.
Topics: Animals; Humans; Neocortex; Neuronal Plasticity; Puberty; Sexual Maturation
PubMed: 27590721
DOI: 10.1016/j.brainres.2016.08.042 -
Nature Reviews. Endocrinology Aug 2016The gonadotropin-releasing hormone (GnRH) neuronal network generates pulse and surge modes of gonadotropin secretion critical for puberty and fertility. The arcuate... (Review)
Review
The gonadotropin-releasing hormone (GnRH) neuronal network generates pulse and surge modes of gonadotropin secretion critical for puberty and fertility. The arcuate nucleus kisspeptin neurons that innervate the projections of GnRH neurons in and around their neurosecretory zone are key components of the pulse generator in all mammals. By contrast, kisspeptin neurons located in the preoptic area project to GnRH neuron cell bodies and proximal dendrites and are involved in surge generation in female rodents (and possibly other species). The hypothalamic-pituitary-gonadal axis develops embryonically but, apart from short periods of activation immediately after birth, remains suppressed through a combination of gonadal and non-gonadal mechanisms. At puberty onset, the pulse generator reactivates, probably owing to progressive stimulatory influences on GnRH neurons from glial and neurotransmitter signalling, and the re-emergence of stimulatory arcuate kisspeptin input. In females, the development of pulsatile gonadotropin secretion enables final maturation of the surge generator that ultimately triggers the first ovulation. Representation of the GnRH neuronal network as a series of interlocking functional modules could help conceptualization of its functioning in different species. Insights into pulse and surge generation are expected to aid development of therapeutic strategies ameliorating pubertal disorders and infertility in the clinic.
Topics: Animals; Brain; Female; Fertility; Gonadotropin-Releasing Hormone; Humans; Neurons; Puberty; Sexual Maturation
PubMed: 27199290
DOI: 10.1038/nrendo.2016.70 -
Best Practice & Research. Clinical... Jun 2019The onset of puberty strongly depends on organizational processes taking place during the fetal and early postnatal life. Therefore, exposure to environmental pollutants... (Review)
Review
The onset of puberty strongly depends on organizational processes taking place during the fetal and early postnatal life. Therefore, exposure to environmental pollutants such as Endocrine disrupting chemicals (EDCs) during critical periods of development can result in delayed/advanced puberty and long-term reproductive consequences. Human evidence of altered pubertal timing after exposure to endocrine disrupting chemicals is equivocal. However, the age distribution of pubertal signs points to a skewed distribution towards earliness for initial pubertal stages and towards lateness for final pubertal stages. Such distortion of distribution is a recent phenomenon and suggests environmental influences including the possible role of nutrition, stress and endocrine disruptors. Rodent and ovine studies indicate a role of fetal and neonatal exposure to EDCs, along the concept of early origin of health and disease. Such effects involve neuroendocrine mechanisms at the level of the hypothalamus where homeostasis of reproduction is programmed and regulated but also peripheral effects at the level of the gonads or the mammary gland.
Topics: Animals; Endocrine Disruptors; Environmental Pollutants; Female; Homeostasis; Humans; Hypothalamus; Male; Puberty; Puberty, Precocious
PubMed: 31401055
DOI: 10.1016/j.beem.2019.101300 -
Frontiers in Neuroendocrinology Jan 2015Substantial progress has been made in recent years toward deciphering the molecular and genetic underpinnings of the pubertal process. The availability of powerful new... (Review)
Review
Substantial progress has been made in recent years toward deciphering the molecular and genetic underpinnings of the pubertal process. The availability of powerful new methods to interrogate the human genome has led to the identification of genes that are essential for puberty to occur. Evidence has also emerged suggesting that the initiation of puberty requires the coordinated activity of gene sets organized into functional networks. At a cellular level, it is currently thought that loss of transsynaptic inhibition, accompanied by an increase in excitatory inputs, results in the pubertal activation of GnRH release. This concept notwithstanding, a mechanism of epigenetic repression targeting genes required for the pubertal activation of GnRH neurons was recently identified as a core component of the molecular machinery underlying the central restraint of puberty. In this chapter we will discuss the potential contribution of various mechanisms of epigenetic regulation to the hypothalamic control of female puberty.
Topics: Animals; Epigenesis, Genetic; Female; Gonadotropin-Releasing Hormone; Humans; Hypothalamus; Neurons; Puberty; Sexual Maturation
PubMed: 25171849
DOI: 10.1016/j.yfrne.2014.08.003 -
Journal of Research on Adolescence :... Mar 2019Over the past two decades, there has been a tremendous increase in our understanding of structural and functional brain development in adolescence. However,... (Review)
Review
Over the past two decades, there has been a tremendous increase in our understanding of structural and functional brain development in adolescence. However, understanding the role of puberty in this process has received much less attention. This review examines this relationship by summarizing recent research studies where the role of puberty was investigated in relation to brain structure, connectivity, and task-related functional magnetic resonance imaging (fMRI). The studies together suggest that puberty may contribute to adolescent neural reorganization and maturational advancement, and sex differences also emerge in puberty. The current body of work shows some mixed results regarding impact and exact direction of pubertal influence. We discuss several limitations of current studies and propose future directions on how to move the field forward.
Topics: Adolescent; Adolescent Behavior; Adolescent Development; Adolescent Health; Brain; Female; Humans; Magnetic Resonance Imaging; Male; Neuroimaging; Puberty; Sex Characteristics; Sexual Maturation; Social Behavior; Theory of Mind
PubMed: 30869842
DOI: 10.1111/jora.12408 -
International Journal of Environmental... Nov 2021Adolescent pregnancy (occurring < age 20) is considered a public health problem that creates and perpetuates inequities, affecting not only women, but societies as a... (Review)
Review
Adolescent pregnancy (occurring < age 20) is considered a public health problem that creates and perpetuates inequities, affecting not only women, but societies as a whole globally. The efficacy of current approaches to reduce its prevalence is limited. Most existing interventions focus on outcomes without identifying or addressing upstream social and biological causes. Current rhetoric revolves around the need to change girls' individual behaviours during adolescence and puberty. Yet, emerging evidence suggests risk for adolescent pregnancy may be influenced by exposures taking place much earlier during development, starting as early as gametogenesis. Furthermore, pregnancy risks are determined by complex interactions between socio-structural and ecological factors including housing and food security, family structure, and gender-based power dynamics. To explore these interactions, we merge three complimentary theoretical frameworks: "Eco-Social", "Life History" and "Developmental Origins of Health and Disease". We use our new lens to discuss social and biological determinants of two key developmental milestones associated with age at first birth: age at girls' first menstrual bleed (menarche) and age at first sexual intercourse (coitarche). Our review of the literature suggests that promoting stable and safe environments starting at conception (including improving economic and social equity, in addition to gender-based power dynamics) is paramount to effectively curbing adolescent pregnancy rates. Adolescent pregnancy exacerbates and perpetuates social inequities within and across generations. As such, reducing it should be considered a key priority for public health and social change agenda.
Topics: Adolescent; Adult; Female; Humans; Menarche; Pregnancy; Pregnancy in Adolescence; Puberty; Young Adult
PubMed: 34831907
DOI: 10.3390/ijerph182212152 -
Criminal Behaviour and Mental Health :... Jun 2020Early puberty is associated with higher than average risk of antisocial behaviour, both in girls and boys. Most studies of such association, however, have focused on... (Review)
Review
BACKGROUND
Early puberty is associated with higher than average risk of antisocial behaviour, both in girls and boys. Most studies of such association, however, have focused on psychosocial mediating and moderating factors. Few refer to coterminous hormonal measures.
AIM
The aim of this review is to consider the role of hormonal markers as potential mediating or moderating factors between puberty timing and antisocial behaviour.
METHOD
A systematic literature search was conducted searching Medline, Embase, Web of Science, Scopus, Psycinfo, Cochrane and Google Scholar.
RESULTS
Just eight studies were found to fit criteria, all cross-sectional. Measurements were too heterogeneous to allow meta-analysis. The most consistent associations found were between adrenal hormones-both androgens and cortisol-which were associated with early adrenarche and antisocial behaviours in girls and later adrenarche and antisocial behaviour in boys.
CONCLUSIONS
The findings from our review suggest that longitudinal studies to test bidirectional hormone-behaviour associations with early or late puberty would be worthwhile. In view of the interactive processes between hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes, integrated consideration of the hormonal end products is recommended.
Topics: Adolescent; Adolescent Behavior; Adrenarche; Androgens; Antisocial Personality Disorder; Child; Female; Gonadal Steroid Hormones; Gonadotropins, Pituitary; Hormones; Humans; Hydrocortisone; Male; Menarche; Puberty; Sexual Maturation; Time Factors
PubMed: 32535969
DOI: 10.1002/cbm.2149 -
Developmental Cognitive Neuroscience Apr 2023Continuous body temperature is a rich source of information on hormonal status, biological rhythms, and metabolism, all of which undergo stereotyped change across... (Review)
Review
Continuous body temperature is a rich source of information on hormonal status, biological rhythms, and metabolism, all of which undergo stereotyped change across adolescence. Due to the direct actions of these dynamic systems on body temperature regulation, continuous temperature may be uniquely suited to monitoring adolescent development and the impacts of exogenous reproductive hormones or peptides (e.g., hormonal contraception, puberty blockers, gender affirming hormone treatment). This mini-review outlines how traditional methods for monitoring the timing and tempo of puberty may be augmented by markers derived from continuous body temperature. These features may provide greater temporal precision, scalability, and reduce reliance on self-report, particularly in females. Continuous body temperature data can now be gathered with ease across a variety of wearable form factors, providing the opportunity to develop tools that aid in individual, parental, clinical, and researcher awareness and education.
Topics: Female; Adolescent; Humans; Adolescent Development; Body Temperature; Puberty
PubMed: 36821877
DOI: 10.1016/j.dcn.2023.101221 -
The Journal of Clinical Endocrinology... Aug 2023Accelerated early growth and early timing of puberty or pubertal variant have been noticed as risk factors for metabolic syndrome, more frequently observed in children... (Review)
Review
Accelerated early growth and early timing of puberty or pubertal variant have been noticed as risk factors for metabolic syndrome, more frequently observed in children born small for gestational age (SGA) or children with premature adrenarche (PA). Children with SGA, especially if they make an accelerated catch-up growth in early life, carry a higher risk for long-term metabolic consequences, such as type 2 diabetes, insulin resistance, and cardiovascular diseases. Furthermore, multiple studies support that these children, either born SGA or with a history of PA, may have earlier pubertal timing, which is also associated with various metabolic risks. This review aims to summarize the recent studies investigating the association between early infantile growth, the timing of puberty, and metabolic risks to expand our knowledge and gain more insight into the underlying pathophysiology.
Topics: Infant, Newborn; Female; Humans; Child; Diabetes Mellitus, Type 2; Puberty; Infant, Small for Gestational Age; Fetal Growth Retardation; Metabolic Syndrome
PubMed: 37029976
DOI: 10.1210/clinem/dgad202