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Animal : An International Journal of... May 2023This article reviews the scientific literature on puberty with a focus on ruminants and draws inference, where appropriate, from recent findings in transgenic mouse... (Review)
Review
This article reviews the scientific literature on puberty with a focus on ruminants and draws inference, where appropriate, from recent findings in transgenic mouse models and human pathology. Early genetic determinants of puberty have been discovered in humans suffering from hypogonadotropic hypogonadism or central precocious puberty. Transgenic mouse models selected on the basis of the causative defective genes helped in discovering the cellular and molecular mechanisms involved. Most of the genes found are involved in the development of neuroendocrine networks during embryo development and early postnatal life. Notwithstanding that the development of neuroendocrine networks takes place early in puberty, a delay or acceleration in the development of Gonadotropin Releasing Hormone (GnRH) neurons has an impact on puberty onset inducing a delay or an advance, respectively. Among the genes discovered in humans and laboratory models, only a few of them displayed polymorphisms associated with advanced sexual maturity, but also marbling, growth traits and callipygian conformation. This could be related to the fact that rather than puberty onset, most research monitored sexual maturity. Sexual maturity occurs after puberty onset and involves factors regulating the maturation of gonads and in the expression of sexual behaviour. The association with growth and metabolic traits is not surprising since nutrition is the major environmental factor that will act on late genetic determinants of puberty onset. However, a recent hypothesis emerged suggesting that it is the postnatal activation of the GnRH neuronal network that induces the acceleration of growth and weight gain. Hence, nutritional factors need the activation of GnRH neurons first before acting on late genetic determinants. Moreover, nutritional factors can also affect the epigenetic landscape of parental gamete's genome with the consequence of specific methylation of genes involved in GnRH neuron development in the embryo. Season is another important regulator of puberty onset in seasonal small ruminants and appears to involve the same mechanisms that are involved in seasonal transition in adults. The social environment is also an underestimated factor affecting puberty onset in domestic ruminants, most research studies focused on olfactory cues, but the genetic basis has not heretofore been adequately tackled by the scientific community. Additionally, there is some evidence to suggest transgenerational effects exist, in that nutritional and social cues to which parents were exposed, could affect the epigenetic landscape of parental gametes resulting in the epigenetic regulation of early genetic determinants of puberty onset in their offspring.
Topics: Mice; Humans; Animals; Sexual Maturation; Epigenesis, Genetic; Puberty; Gonadotropin-Releasing Hormone; Ruminants; Mice, Transgenic
PubMed: 37567653
DOI: 10.1016/j.animal.2023.100812 -
World Review of Nutrition and Dietetics 2023NA. (Review)
Review
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Topics: Humans; Malnutrition; Puberty; Growth; Body Height
PubMed: 36948171
DOI: 10.1159/000527935 -
Child and Adolescent Psychiatric... Oct 2023As a child and adolescent psychiatrist, I am aware that puberty is a challenging experience for many adolescents and parents. As a parent of a transgender adolescent, I... (Review)
Review
As a child and adolescent psychiatrist, I am aware that puberty is a challenging experience for many adolescents and parents. As a parent of a transgender adolescent, I have seen the ways in which the experience of puberty is similar to and different from that of cisgender adolescents. In this article, I describe my thought process behind going forward with several medical interventions for my transgender child and relate this to broader observations about parents and puberty.
Topics: Adolescent; Child; Humans; Transgender Persons; Parents; Puberty
PubMed: 37739640
DOI: 10.1016/j.chc.2023.05.005 -
Trends in Endocrinology and Metabolism:... May 2022Normal growth pattern variations [i.e., constitutional advancement and constitutional delay of growth and puberty (CAGP and CDGP)] are the mirror image of each other and... (Review)
Review
Normal growth pattern variations [i.e., constitutional advancement and constitutional delay of growth and puberty (CAGP and CDGP)] are the mirror image of each other and are associated with early puberty (EP) and delayed puberty (DP), respectively. Differences between CAGP and CDGP relate not only to auxological characteristics (height, weight) but also to insulin-like growth factor-1 (IGF-1). IGF-1 levels in CAGP are above average whereas in CDGP they are below average, suggesting a role for IGF-1 in the induction of these growth patterns. Herein, we provide data suggesting that early activation of the growth hormone (GH)/IGF-1 axis induces the growth pattern of CAGP. Moreover, we suggest that IGF-1 is a decisive factor for the release of the gonadotropin-releasing hormone (GnRH) inhibition brake that occurs in prepuberty. It is therefore crucial for puberty onset.
Topics: Growth Hormone; Human Growth Hormone; Humans; Insulin-Like Growth Factor I; Puberty
PubMed: 35331614
DOI: 10.1016/j.tem.2022.02.004 -
Tidsskrift For Den Norske Laegeforening... May 2021
Topics: Humans; Puberty
PubMed: 33950643
DOI: 10.4045/tidsskr.21.0210 -
The Journal of Adolescent Health :... Jan 2020
Topics: Adolescent; Female; Gender Equity; Gender Identity; Humans; Male; Puberty
PubMed: 31866032
DOI: 10.1016/j.jadohealth.2019.10.012 -
The New Bioethics : a Multidisciplinary... Sep 2022Gender dysphoria is a persistent distress about one's assigned gender. Referrals regarding gender dysphoria have recently greatly increased, often of a form that is... (Review)
Review
Gender dysphoria is a persistent distress about one's assigned gender. Referrals regarding gender dysphoria have recently greatly increased, often of a form that is rapid in onset. The sex ratio has changed, most now being natal females. Mental health issues pre-date the dysphoria in most. Puberty blockers are offered in clinics to help the child avoid puberty. Puberty blockers have known serious side effects, with uncertainty about their long-term use. They do not improve mental health. Without medication, most will desist from the dysphoria in time. Yet over 90% of those treated with puberty blockers progress to cross-sex hormones and often surgery, with irreversible consequences. The brain is biologically and socially immature in childhood and unlikely to understand the long-term consequences of treatment. The prevailing culture to affirm the dysphoria is critically reviewed. It is concluded that children are unable to consent to the use of puberty blockers.
Topics: Child; Female; Gender Dysphoria; Gender Identity; Gonadal Steroid Hormones; Humans; Informed Consent; Puberty
PubMed: 35758886
DOI: 10.1080/20502877.2022.2088048 -
Nature Reviews. Endocrinology Jan 2022
Topics: Humans; Obesity; Puberty; Receptor, Melanocortin, Type 3
PubMed: 34819624
DOI: 10.1038/s41574-021-00602-1 -
Nature Reviews. Endocrinology Feb 2022
Topics: Humans; Obesity; Polymorphism, Single Nucleotide; Puberty
PubMed: 34848875
DOI: 10.1038/s41574-021-00616-9 -
Developmental Cognitive Neuroscience Apr 2023Pubertal development is a potential trigger for increases in risk-taking behaviours during adolescence. Here, we sought to investigate the relationship between puberty...
Pubertal development is a potential trigger for increases in risk-taking behaviours during adolescence. Here, we sought to investigate the relationship between puberty and neural activation during risky decision-making in males using functional magnetic resonance imaging (fMRI). Forty-seven males aged 12.5-14.5 years completed an fMRI risk-taking task (BART) and reported their tendencies for risky decision-making using a self-report questionnaire. Puberty was assessed through self-reported pubertal status and salivary testosterone levels. Testosterone concentration, but not physical pubertal status, was positively correlated with self-reported risk-taking behaviour, while neither was correlated with BART performance. Across the whole sample, participants had greater activation of the bilateral nucleus accumbens and right caudate on trials when they made a successful risky decision compared to trials when they made a safe choice or when their risky decision was unsuccessful. There was a negative correlation between pubertal stage and brain activation during unsuccessful risky decision-making trials compared within unsuccessful control trials. Males at a lower stage of pubertal development showed increased activation in the left insula, right cingulate cortex, dorsomedial prefrontal cortex (dmPFC), right putamen and right orbitofrontal cortex (OFC) relative to more pubertally mature males during trials when they chose to take a risk and the balloon popped compared to when they watched the computer make an unsuccessful risky decision. Less pubertally mature males also showed greater activation in brain regions including the dmPFC, right temporal and frontal cortices, right OFC, right hippocampus and occipital cortex in unsuccessful risky trials compared to successful risky trials. These results suggest a puberty-related shift in neural activation within key brain regions when processing outcomes of risky decisions, which may reduce their sensitivity to negative feedback, and in turn contribute to increases in adolescent risk-taking behaviours.
Topics: Humans; Male; Adolescent; Decision Making; Risk-Taking; Brain; Puberty; Brain Mapping; Magnetic Resonance Imaging; Testosterone
PubMed: 36965437
DOI: 10.1016/j.dcn.2023.101230