Development of the Hypothalamic‐Pituitary‐Ovarian Axis

Apter, Dan

doi:10.1111/j.1749-6632.1997.tb52125.x

Cited by 64 publications

(34 citation statements)

References 52 publications

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“…For example, leptin levels are predictive of early menarche, 38 and levels are higher among black girls than white girls. 39 Racial differences may also exist in other characteristics that have been suggested to influence pubertal development, such as the secretion of hormones by the hypothalamus, anterior pituitary, and ovary 40 ; social stress 41 ; organic pollutants 42 ; and hormone-containing hair products. 43 The most important limitation of the current study may be our use of self-reported menarcheal age.…”

Section: Discussionmentioning

confidence: 99%

Relation of Age at Menarche to Race, Time Period, and Anthropometric Dimensions: The Bogalusa Heart Study

et al. 2002

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ABSTRACT. Objective. To assess secular trends in menarcheal age between 1973 and 1994 and to determine whether childhood levels of height, weight, and skinfold thicknesses can account for racial (white/black) differences in menarcheal age.Methods. Data from 7 cross-sectional examinations of school-aged children, with menarcheal age obtained through interviews, were used for both cross-sectional (11 218 observations) and longitudinal (n ‫؍‬ 2058) analyses. In the latter analyses, the baseline examination was performed between ages 5.0 and 9.9 years, and the mean follow-up was 6 years.Results. Black girls experienced menarche, on average, 3 months earlier than did white girls (12.3 vs 12.6 years), and during the 20-year study period, the median menarcheal age decreased by approximately 9.5 months among black girls versus approximately 2 months among white girls. As compared with 5-to 9-year-old white girls, black girls were taller and weighed more, characteristics that were predictive of a relatively early (before age 11.0 years) menarche. However, even after adjustment for weight, height, and other characteristics, the rate of early menarche remained 1.4-fold higher among black girls than among white girls.Conclusions. Additional study of the determinants of menarcheal age is needed, as the timing of pubertal maturation may influence the risk of various diseases in adulthood. Pediatrics 2002;110(4). URL: http://www. pediatrics.org/cgi/content/full/110/4/e43; menarche, obesity, blacks, height, secular trend.ABBREVIATIONS. BMI, body mass index; RR, rate ratio. B lack girls in the United States undergo sexual development at younger ages than do white girls. [1][2][3][4][5] In a study of 17 000 girls, for example, mean menarcheal ages were 12.2 years (blacks) and 12.9 years (whites), 4 a racial difference consistent with those that have been observed in the development of breast and pubic hair. 2,3 The timing of these events may influence the risk of various diseases in adulthood, and an early menarche has been associated with an increased risk for breast cancer, 6 obesity, 7-9 and spontaneous abortion. 10 The reasons for these racial differences in menarcheal age are uncertain, but several characteristics, such as obesity, 11-14 height, 3,8,13-15 and skeletal maturation, 16 -18 are known to influence sexual development. Furthermore, the dramatic decrease in menarcheal age between the mid-1800s and the mid-1900s 19 may be related to the changes in childhood heights and weights that occurred during this period as a result of improved nutritional status. As compared with similarly aged white girls, black girls are more advanced skeletally (after age 9 years), 20 are taller, 3,21 and are heavier. 3 It is uncertain, however, whether these characteristics account for the earlier sexual development of black girls in the United States.The objectives of the current study were to examine changes in the menarcheal ages of girls between 1973 and 1994 and to determine whether differences between black and white girls are attri...

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Section: Discussionmentioning

confidence: 99%

Relation of Age at Menarche to Race, Time Period, and Anthropometric Dimensions: The Bogalusa Heart Study

et al. 2002

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“…[196]). Yet, initiation of puberty does not rely on alterations in sensitivity to gonadal steroid feedback; there are species differences in these feedback systems [428], and pubertal activation of pulsatile GnRH release is evident even in patients with gonadal agenesis [21].…”

Section: Attenuation Of Inhibitory Tonementioning

confidence: 99%

The adolescent brain and age-related behavioral manifestations

Spear

2000

Neuroscience & Biobehavioral Reviews

4,742

110

4,301

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To successfully negotiate the developmental transition between youth and adulthood, adolescents must maneuver this often stressful period while acquiring skills necessary for independence. Certain behavioral features, including age-related increases in social behavior and risk-taking/novelty-seeking, are common among adolescents of diverse mammalian species and may aid in this process. Reduced positive incentive values from stimuli may lead adolescents to pursue new appetitive reinforcers through drug use and other risk-taking behaviors, with their relative insensitivity to drugs supporting comparatively greater per occasion use. Pubertal increases in gonadal hormones are a hallmark of adolescence, although there is little evidence for a simple association of these hormones with behavioral change during adolescence. Prominent developmental transformations are seen in prefrontal cortex and limbic brain regions of adolescents across a variety of species, alterations that include an apparent shift in the balance between mesocortical and mesolimbic dopamine systems. Developmental changes in these stressor-sensitive regions, which are critical for attributing incentive salience to drugs and other stimuli, likely contribute to the unique characteristics of adolescence. ᭧

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“…This is an important question for several reasons. First, the pubertal period is associated with dramatic changes in circulating hormones, comparable to, if not greater than, (Apter, 1997) changes occurring during reproductive aging (Hammond, 1996). Second, hormone-associated changes in brain plasticity such as neurite outgrowth, spinogenesis, synaptogenesis, and expression of neurotransmitter receptors are observed during puberty in neuroendocrine brain regions (Anderson, 1982;Cottrell et al, 2006;Gore et al, 1996;Matsumoto & Arai, 1976;Reier et al, 1977); however such analyses have not been systematically studied in hippocampal brain regions.…”

Section: Introductionmentioning

confidence: 99%

“…Pubertal developmental in female mammals is characterized by dramatic increases in circulating estradiol concentrations (Apter, 1997;see Table 1). This hormone acts on targets throughout the body and the brain, where estrogen receptors are widely expressed (Chakraborty & Gore, 2004;Mitra et al, 2003).…”

Section: Hippocampal Plasticity and Pubertymentioning

confidence: 99%

Postpubertal decrease in hippocampal dendritic spines of female rats

Yıldırım

Mapp

Janssen

et al. 2008

Experimental Neurology

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Hippocampal dendritic spine and synapse numbers in female rats vary across the estrous cycle and following experimental manipulation of hormone levels in adulthood. Based on behavioral studies demonstrating that learning patterns are altered following puberty, we hypothesized that dendritic spine number in rat hippocampal CA1 region would change post-pubertally. Female SpragueDawley rats were divided into prepubertal (postnatal day (P) 22), peripubertal (P35) and postpubertal (P49) groups, with the progression of puberty evaluated by vaginal opening, and estrous cyclicity subsequently assessed by daily vaginal smears. Spinophilin immunoreactivity in dendritic spines was used as an index of spinogenesis in area CA1 stratum radiatum (CA1sr) of hippocampus. First, electron microscopy analyses confirmed the presence of spinophilin specifically in dendritic spines of CA1sr, supporting spinophilin as a reliable marker of hippocampal spines in young female rats. Second, stereologic analysis was performed to assess the total number of spinophilin-immunoreactive puncta (i.e. spines) and CA1sr volume in developing rats. Our results indicated that the number of spinophilin-immunoreactive spines in CA1sr was decreased 46% in the post-pubertal group compared to the two younger groups, whereas the volume of the hippocampus underwent an overall increase during this same developmental time frame. Third, to determine a potential role of estradiol in this process, an additional group of rats was ovariectomized (OVX) prepubertally at P22, then treated with estradiol or vehicle at P35, and spinophilin quantified as above in rats perfused on P49. No difference in spinophilin puncta number was found in OVX rats between the two hormone groups, suggesting that this developmental decrease is independent of peripheral estradiol. These changes in spine density coincident with puberty may be related to altered hippocampal plasticity and synaptic consolidation at this phase of maturity.

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Development of the Hypothalamic‐Pituitary‐Ovarian Axis

Cited by 64 publications

References 52 publications

Relation of Age at Menarche to Race, Time Period, and Anthropometric Dimensions: The Bogalusa Heart Study

Relation of Age at Menarche to Race, Time Period, and Anthropometric Dimensions: The Bogalusa Heart Study

The adolescent brain and age-related behavioral manifestations

Postpubertal decrease in hippocampal dendritic spines of female rats

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