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Neuroscience and Biobehavioral Reviews Nov 2018The transition from adolescence to adulthood is characterized by improvements in higher-order cognitive abilities and corresponding refinements of the structure and... (Review)
Review
The transition from adolescence to adulthood is characterized by improvements in higher-order cognitive abilities and corresponding refinements of the structure and function of the brain regions that support them. Whereas the neurobiological mechanisms that govern early development of sensory systems are well-understood, the mechanisms that drive developmental plasticity of association cortices, such as prefrontal cortex (PFC), during adolescence remain to be explained. In this review, we synthesize neurodevelopmental findings at the cellular, circuit, and systems levels in PFC and evaluate them through the lens of established critical period (CP) mechanisms that guide early sensory development. We find remarkable correspondence between these neurodevelopmental processes and the mechanisms driving CP plasticity, supporting the hypothesis that adolescent development is driven by CP mechanisms that guide the rapid development of neurobiology and cognitive ability during adolescence and their subsequent stability in adulthood. Critically, understanding adolescence as a CP not only provides a mechanism for normative adolescent development, it provides a framework for understanding the role of experience and neurobiology in the emergence of psychopathology that occurs during this developmental period.
Topics: Adolescent; Brain; Cognition; Humans; Sexual Maturation
PubMed: 30201220
DOI: 10.1016/j.neubiorev.2018.09.005 -
Nature Nov 2021The state of somatic energy stores in metazoans is communicated to the brain, which regulates key aspects of behaviour, growth, nutrient partitioning and development....
The state of somatic energy stores in metazoans is communicated to the brain, which regulates key aspects of behaviour, growth, nutrient partitioning and development. The central melanocortin system acts through melanocortin 4 receptor (MC4R) to control appetite, food intake and energy expenditure. Here we present evidence that MC3R regulates the timing of sexual maturation, the rate of linear growth and the accrual of lean mass, which are all energy-sensitive processes. We found that humans who carry loss-of-function mutations in MC3R, including a rare homozygote individual, have a later onset of puberty. Consistent with previous findings in mice, they also had reduced linear growth, lean mass and circulating levels of IGF1. Mice lacking Mc3r had delayed sexual maturation and an insensitivity of reproductive cycle length to nutritional perturbation. The expression of Mc3r is enriched in hypothalamic neurons that control reproduction and growth, and expression increases during postnatal development in a manner that is consistent with a role in the regulation of sexual maturation. These findings suggest a bifurcating model of nutrient sensing by the central melanocortin pathway with signalling through MC4R controlling the acquisition and retention of calories, whereas signalling through MC3R primarily regulates the disposition of calories into growth, lean mass and the timing of sexual maturation.
Topics: Adolescent; Aged, 80 and over; Animals; Child; Child Development; Estrous Cycle; Female; Homozygote; Humans; Hypothalamus; Insulin-Like Growth Factor I; Male; Melanocortins; Menarche; Mice; Nutritional Status; Phenotype; Puberty; Receptor, Melanocortin, Type 3; Sexual Maturation; Time Factors; Weight Gain
PubMed: 34732894
DOI: 10.1038/s41586-021-04088-9 -
Best Practice & Research. Clinical... Jan 2022Puberty marks the end of childhood and is a period when individuals undergo physiological and psychological changes to achieve sexual maturation and fertility. The onset... (Review)
Review
Puberty marks the end of childhood and is a period when individuals undergo physiological and psychological changes to achieve sexual maturation and fertility. The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Pubertal onset is regulated by genetic, nutritional, environmental, and socio-economic factors. Disturbances affecting pubertal timing result in adverse health conditions later in life. Human genetic studies show that around 50-80% of the variation in pubertal onset is genetically determined. The genetic control of pubertal timing has been a field of active investigation in attempt to better understand the neuroendocrine control of this relevant period of life. Large populational studies and patient cohort-based studies have provided insights into the genetic regulation of pubertal onset. In this review, we discuss these discoveries and discuss potential mechanisms for how implicated genes may affect pubertal timing.
Topics: Gonadotropin-Releasing Hormone; Humans; Puberty; Puberty, Delayed; Sexual Maturation
PubMed: 35183440
DOI: 10.1016/j.beem.2022.101618 -
Annals of Allergy, Asthma & Immunology... May 2018To summarize the current literature on the sex disparity in asthma and the role of sex hormone signaling in allergic and neutrophilic airway inflammation. (Review)
Review
OBJECTIVE
To summarize the current literature on the sex disparity in asthma and the role of sex hormone signaling in allergic and neutrophilic airway inflammation.
DATA SOURCES
PubMed and Centers for Disease Control and Prevention health surveys were searched.
STUDY SELECTIONS
Clinical and epidemiologic studies in children and adults as well as animal models of asthma were included in this review.
RESULTS
Compared with males, females have an increase in asthma prevalence starting around puberty, and fluctuations in hormones during menstruation, pregnancy, and menopause are associated with changes in asthma symptoms. Animal studies using genetic deletions of estrogen receptors or androgen receptors have shown that estrogen signaling promotes and androgen signaling attenuates allergen-mediated type 2 airway inflammation. Furthermore, animal studies have found that ovarian hormones are important for interleukin 17A-mediated airway inflammation.
CONCLUSION
Sex hormones are important in regulating asthma pathogenesis. However, additional studies need to be conducted to further elucidate how sex hormones are initiating and driving the inflammatory response(s) in asthma. Determining these pathways will provide the foundation necessary for the development of treatment strategies and potentially new therapeutics for patients, in particular females, with asthma.
Topics: Adult; Androgens; Animals; Asthma; Child; Estrogens; Female; Gene Expression Regulation, Developmental; Gonadal Steroid Hormones; Humans; Interleukin-17; Male; Menopause; Menstrual Cycle; Mice; Pregnancy; Sex Factors; Sexual Maturation; Signal Transduction
PubMed: 29410216
DOI: 10.1016/j.anai.2018.01.016 -
Ciencia & Saude Coletiva Sep 2022This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based...
This study aimed to investigate the relationship between sexual maturation and anthropometric and blood pressure indicators in teenagers. This was a population-based cross-sectional study, conducted with 345 teenagers, aged 10 to 19 years, between 2018 and 2020. In this study, data referent to sociodemographic and anthropometric variables, blood pressure, and sexual maturation were collected. The data analysis was performed by applying the Principle Component Analysis (PCA), which generated three components and then tested the correlation between sexual maturation and the generated components. Most of the teenagers were female (53%), normotensive (66.1%), and with a normal weight (73%). A positive correlation was found between breast development and component 1 and component 2, as well as a negative correlation between the breasts and component 3. In the boys, the development of genitals and pubic hair was positively correlated with component 2 and inversely correlated with component 3. It could therefore be concluded that there is a relationship between sexual maturation and the anthropometric and blood pressure indicators, which proved to be representative variables for cardiovascular risk in teenagers, even if not in their entirety.
Topics: Adolescent; Anthropometry; Blood Pressure; Cross-Sectional Studies; Female; Humans; Male; Sexual Maturation
PubMed: 36000648
DOI: 10.1590/1413-81232022279.04622022 -
Current Opinion in Endocrinology,... Feb 2018The current review summarizes recent epidemiologic data demonstrating the effects of endocrine disrupting compounds (EDCs) on the timing of puberty and highlights the... (Review)
Review
PURPOSE OF REVIEW
The current review summarizes recent epidemiologic data demonstrating the effects of endocrine disrupting compounds (EDCs) on the timing of puberty and highlights the complexity of understanding the interplay of environmental and genetic factors on pubertal timing.
RECENT FINDINGS
In girls, there have been mixed results, with some exposures being associated with earlier timing of puberty, and some with later puberty. In boys, prepubertal exposures to nondioxin-like polychlorinated biphenyls accelerate puberty, whereas levels of insecticides, dioxin-like compounds, organochlorine pesticides, and lead delay puberty.
SUMMARY
The effects of EDCs on pubertal timing are sexually dimorphic, compound specific, and varies according to the window of exposure. These studies confirm that low-level exposures to a mix of environmental compounds may mask the effects of individual compounds and complicate our ability to translate data from animal studies to human health and to fully understand the clinical implications of environmental epidemiology studies.
Topics: Animals; Endocrine Disruptors; Environmental Exposure; Female; Humans; Male; Pesticides; Puberty; Sexual Maturation; Time Factors
PubMed: 29135489
DOI: 10.1097/MED.0000000000000377 -
Current Biology : CB Apr 2022Adequate nutrition is essential for normal reproductive function, which is vital for species to survive. In humans and other mammals, starvation and undernutrition...
Adequate nutrition is essential for normal reproductive function, which is vital for species to survive. In humans and other mammals, starvation and undernutrition deplete fat reserves and cause weight loss, attenuating the function of the reproductive axis and causing hypogonadism. Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) spend 7 months of every year in hibernation without food and water. Hibernating squirrels alternate between periods of torpor and interbout arousal (IBA), when animals temporarily return to an active-like state. The physiological significance of IBA is unclear, but it is thought to be essential for hibernation in animals that drop their body temperature to 2°C-4°C during torpor. Here, we report that juvenile male ground squirrels initiate reproductive maturation during their first hibernation season, despite prolonged undernutrition and profound weight loss. We show that the hypothalamic reproductive axis undergoes activation during interbout arousals in the middle of hibernation, triggering production of luteinizing hormone and testosterone, and promoting testicular growth. Initiation of sexual maturation is circannually entrained and is independent of physiological state, ambient temperature, and food availability. Our study suggests a role for interbout arousals during hibernation and uncovers the neurophysiological mechanism of reproductive axis activation during conditions of extreme negative energy balance. VIDEO ABSTRACT.
Topics: Animals; Hibernation; Male; Malnutrition; Sciuridae; Sexual Maturation; Weight Loss
PubMed: 35245461
DOI: 10.1016/j.cub.2022.02.032 -
Jornal de Pediatria 2020To evaluate height, sexual maturation, and the difference between final and expected height in girls with juvenile idiopathic arthritis and no glucocorticoid treatment...
OBJECTIVE
To evaluate height, sexual maturation, and the difference between final and expected height in girls with juvenile idiopathic arthritis and no glucocorticoid treatment for at least six months, as compared to a group of healthy girls.
METHODS
This cross-sectional study involved 44 girls with juvenile idiopathic arthritis, diagnosed according to the International League of Associations for Rheumatology criteria, and 59 healthy controls aged between 8 and 18 (incomplete) years with no comorbid chronic diseases. Demographic data were collected from all participants, and disease and treatment variables were compiled for the patient group. Anthropometric measurements were converted into Z-scores based on World Health Organization standards. Sexual maturation was classified according to Tanner stages.
RESULTS
Body mass index and height Z-scores were lower in girls with juvenile idiopathic arthritis as compared to control participants. These values differed significantly in Tanner stage II. Three (6.8%) girls with juvenile idiopathic arthritis had height-for-age Z-scores <-2 (short stature). Girls with polyarticular juvenile idiopathic arthritis and higher cumulative glucocorticoid doses were significantly more likely to present with short stature. The percentage of prepubertal girls in the juvenile idiopathic arthritis group was significantly higher than that observed in the control group, (p=0.012). Age of menarche, adult height, and the difference between actual and expected height did not differ between groups.
CONCLUSION
These findings suggest that even six months after the suspension of glucocorticoid treatment, children with polyarticular/systemic juvenile idiopathic arthritis subtypes are still susceptible to low height and delayed puberty.
Topics: Adolescent; Arthritis, Juvenile; Body Height; Body Mass Index; Child; Cross-Sectional Studies; Female; Humans; Menarche; Sexual Maturation
PubMed: 30339783
DOI: 10.1016/j.jped.2018.07.015 -
Journal of Research on Adolescence :... Mar 2019In recent decades, theoretical and methodological advances have operated synergistically to advance understanding of puberty and prompt increasingly comprehensive models... (Review)
Review
In recent decades, theoretical and methodological advances have operated synergistically to advance understanding of puberty and prompt increasingly comprehensive models that engage with the temporal, psychosocial, and biological dimensions of this maturational milepost. This integrative overview discusses these theoretical and methodological advances and their implications for research and intervention to promote human development in the context of changing maturational schedules and massive ongoing social transformations.
Topics: Adolescent; Adolescent Development; Adolescent Health; Biological Evolution; Child; Female; Humans; Male; Neurosciences; Puberty; Sexual Maturation
PubMed: 30869841
DOI: 10.1111/jora.12411 -
Frontiers in Neuroendocrinology Jan 2017Adolescence is a transitional period of physical and behavioral development between childhood and adulthood. Puberty is a distinct period of sexual maturation that... (Review)
Review
Adolescence is a transitional period of physical and behavioral development between childhood and adulthood. Puberty is a distinct period of sexual maturation that occurs during adolescence. Since the advent of magnetic resonance imaging (MRI), human studies have largely examined neurodevelopment in the context of age. A breadth of animal findings suggest that sex hormones continue to influence the brain beyond the prenatal period, with both organizational and activational effects occurring during puberty. Given the animal evidence, human MRI research has also set out to determine how puberty may influence otherwise known patterns of age-related neurodevelopment. Here we review structural-based MRI studies and show that pubertal maturation is a key variable to consider in elucidating sex- and individual- based differences in patterns of human brain development. We also highlight the continuing challenges faced, as well as future considerations, for this vital avenue of research.
Topics: Adolescent; Animals; Brain; Female; Gonadal Steroid Hormones; Humans; Magnetic Resonance Imaging; Male; Puberty; Sexual Maturation
PubMed: 28007528
DOI: 10.1016/j.yfrne.2016.12.003