References of "Bourguignon, Jean-Pierre"
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See detailEarly exposure to Aroclor 1254 in vivo disrupts the functional synaptic development of newborn hippocampal granule cells.
Parent, Anne-Simone ULg; Pinson, Anneline ULg; Woods, N. et al

in European Journal of Neuroscience (2016), 44(12), 3001-3010

Neurogenesis in the dentate gyrus is sensitive to endogenous and exogenous factors that influence hippocampal function. Ongoing neurogenesis and the integration of these new neurons throughout life thus ... [more ▼]

Neurogenesis in the dentate gyrus is sensitive to endogenous and exogenous factors that influence hippocampal function. Ongoing neurogenesis and the integration of these new neurons throughout life thus may provide a sensitive indicator of environmental stress. We examined the effects of Aroclor 1254 (A1254), a mixture of polychlorinated biphenyls (PCBs), on the development and function of newly generated dentate granule cells. Early exposure to A1254 has been associated with learning impairment in children, suggesting potential impact on the development of hippocampus and/or cortical circuits. Oral A1254 (from the 6th day of gestation to postnatal day 21) produced the expected increase in PCB levels in brain at postnatal day 21, which persisted at lower levels into adulthood. A1254 did not affect the proliferation or survival of newborn neurons in immature animals nor did it cause overt changes in neuronal morphology. However, A1254 occluded the normal developmental increase in sEPSC frequency in the third post-mitotic week without altering the average sEPSC amplitude. Our results suggest that early exposure to PCBs can disrupt excitatory synaptic function during a period of active synaptogenesis, and thus could contribute to the cognitive effects noted in children exposed to PCBs. [less ▲]

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See detailExposure to endocrine disrupting chemicals and neurodevelopmental alterations.
Pinson, Anneline ULg; Bourguignon, Jean-Pierre ULg; Parent, Anne-Simone ULg

in Andrology (2016), 4(4), 706-22

The developing brain is remarkably malleable as neural circuits are formed and these circuits are strongly dependent on hormones for their development. For those reasons, the brain is very vulnerable to ... [more ▼]

The developing brain is remarkably malleable as neural circuits are formed and these circuits are strongly dependent on hormones for their development. For those reasons, the brain is very vulnerable to the effects of endocrine-disrupting chemicals (EDCs) during critical periods of development. This review focuses on three ubiquitous endocrine disruptors that are known to disrupt the thyroid function and are associated with neurobehavioral deficits: polychlorinated biphenyls, polybrominated diphenyl ethers, and bisphenol A. The human and rodent data suggesting effects of those EDCs on memory, cognition, and social behavior are discussed. Their mechanisms of action go beyond relative hypothyroidism with effects on neurotransmitter release and calcium signaling. [less ▲]

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See detailPuberty from bench to clinic
Bourguignon, Jean-Pierre ULg; Parent, Anne-Simone ULg

Book published by Karger (2016)

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See detailDelayed neuroendocrine sexual maturation in female rats after a very low dose of Bisphenol A through altered GABAergic neurotransmission and opposing effects of a high dose.
Franssen, Delphine ULg; GERARD, Arlette ULg; HENNUY, Benoit ULg et al

in Endocrinology (2016)

Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of gonadotropinreleasing hormone (GnRH) neurosecretion. This work aims at studying disruption of that neuroendocrine event ... [more ▼]

Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of gonadotropinreleasing hormone (GnRH) neurosecretion. This work aims at studying disruption of that neuroendocrine event in females after early exposure to a very low dose of Bisphenol A (BPA), a ubiquitous endocrine disrupting chemical. Female rats were exposed to vehicle or BPA 25 ng/kg.day, 25 g/kg.day, or 5 mg/kg.day from postnatal day (PND) 1 to 5 or 15. Exposure to 25 ng/kg.day of BPA for 5 or 15 days was followed by a delay in developmental reduction of GnRH IPI studied ex vivo on PND 20. After 15 days of exposure to that low dose of BPA, vaginal opening tended to be delayed. In contrast, exposure to BPA 5 mg/kg.day for 15 days resulted in a premature reduction inGnRHIPI and a trend toward early vaginal opening. RNAseq analysis on PND20 indicated that exposure to BPA resulted in opposing dose effectsonthemRNAexpression of hypothalamic genes involved inGABAA neurotransmission. The study of GnRH secretion in vitro in the presence of GABAA receptor agonist/antagonist confirmed an increased or a reduced GABAergic tone after in vivo exposure to the very low or the high dose of BPA, respectively. Overall, we show for the first time that neonatal exposure to BPA leads to opposing dose-dependent effects on the neuroendocrine control of puberty in the female rat. A very low and environmentally relevant dose of BPA delays neuroendocrine maturation related to puberty through increased inhibitory GABAergic neurotransmission. [less ▲]

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See detailCurrent Changes in Pubertal Timing: Revised Vision in Relation with Environmental Factors Including Endocrine Disruptors.
Parent, Anne-Simone ULg; Franssen, Delphine ULg; Fudvoye, Julie ULg et al

in Endocrine development (2016), 29

The aim of this chapter is to revise some common views on changes in pubertal timing. This revision is based on recent epidemiological findings on the clinical indicators of pubertal timing and data on ... [more ▼]

The aim of this chapter is to revise some common views on changes in pubertal timing. This revision is based on recent epidemiological findings on the clinical indicators of pubertal timing and data on environmental factor effects and underlying mechanisms. A current advancement in timing of female puberty is usually emphasized. It appears, however, that timing is also changing in males. Moreover, the changes are towards earliness for initial pubertal stages and towards lateness for final stages in both sexes. Such observations indicate the complexity of environmental influences on pubertal timing. The mechanisms of changes in pubertal timing may involve both the central neuroendocrine control and peripheral effects at tissues targeted by gonadal steroids. While sufficient energy availability is a clue to the mechanism of pubertal development, changes in the control of both energy balance and reproduction may vary under the influence of common determinants such as endocrine-disrupting chemicals (EDCs). These effects can take place right before puberty as well as much earlier, during fetal and neonatal life. Finally, environmental factors can interact with genetic factors in determining changes in pubertal timing. Therefore, the variance in pubertal timing is no longer to be considered under absolutely separate control by environmental and genetic determinants. Some recommendations are provided for evaluation of EDC impact in the management of pubertal disorders and for possible reduction of EDC exposure along the precautionary principle. [less ▲]

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See detailThe effects of perinatal exposure to polychlorinated biphenyls on hippocampal neurogenesis
Pinson, Anneline ULg; Parent, Anne-Simone ULg; chatzi, christina et al

Poster (2015, May)

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See detailPromotion of physical activity among children and adolescents followed for overweight or obesity in
DEWANDRE, Anne-Cécile ULg; HARVENGT, Julie ULg; LAGASSE, Celine ULg et al

in Tijdschrift van de Belgische Kinderarts = Journal du Pédiatre Belge (2015, January), 17(1), 40

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See detailSexually dimorphic effect of gestational exposure to BPA on DNA methylation in the rat placenta
Fudvoye, Julie ULg; Dehan, Pierre ULg; Trooskens, G. et al

in Tijdschrift van de Belgische Kinderarts = Journal du Pédiatre Belge (2015, January), 17(1), 37

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See detailDélinquance des adolescents et maturation pubertaire analysées au travers du timing pubertaire perçu
Glowacz, Fabienne ULg; Bourguignon, Jean-Pierre ULg

in Annales Médico-Psychologiques (2015), 173

The impact of pubertal development on the psychological and social functioning of the teenager arouses a particular interest; the most recent research shows the existence of complex relationships between ... [more ▼]

The impact of pubertal development on the psychological and social functioning of the teenager arouses a particular interest; the most recent research shows the existence of complex relationships between pubertal development and the manifestation of internalized and externalized disorders. Two predominant hypothesis are used for explain influence of pubertal timing on problem behaviors : the maturational deviance theory and the stage termination (early timing) theory. The deviance theory claims that the borderline or abnormal pubertal timing, whether early or late, causes difficulties for adolescent adaptation. The early timing theory suggests that early pubertal timing and the consequent early physical maturation put adolescents at greater risk of adjustment problems because early pubertal maturation interferes with normal progression through the developmental tasks of adolescence. Our study is interested specifically in the links between delinquency during adolescence and pubertal maturation in a population of 141 boys aged between 12 and 18. We measured the pubertal variable starting from the perceived pubertal timing (PPT), which evaluates the teenagers' perception of their pubertal maturation, compared with that of their peers, to understand its impact on various dimensions of the functioning of teenagers: the self-perception (scale of Harter), aggressiveness (scale of Buss and Perry), association with peers and self-reported delinquency (attacks on property and individuals). We began with univariate analyses in order to determine the variables associated with early or late pubertal timing through comparison of scores obtained in those subjects with reference to average maturers. Subsequently, multivariate analyses were used in an attempt to sort out which among the studied factors could be predictor or a determinant of delinquency in relation to pubertal timing. Therefore, stepwise multiple regression analysis was performed. Statistical analyses were run with the SAS software, version 9.1.Our results support the thesis of precocity, the teenagers with an advanced PPT present scores of delinquency and aggressiveness significantly higher than teenagers with a standard PPT. However, the sub-group of teenagers with delayed PPT present raw scores of self-revealed delinquency which are higher than those of teenagers with a standard PPT. These teenagers can be characterized by a significantly higher hostility than the teenagers with a standard PPT. This cognitive dimension of aggressiveness, as evaluated by Buss and Perry, characterizes the functioning of the teenagers with the delayed PPT, who also present poorer self-esteem and dissatisfaction with their physical appearance. On the basis of this assessment, an analysis of multiple regression within each type of PPT aimed at identifying the variables likely to explain the delinquency of teenagers according to their PPT. The results show that the physical factor of aggressiveness is common to the three types of PPT. It is associated with the affiliation with delinquent peers for those teenagers with advanced and normal PPT, whereas for those teenagers with delayed PPT, it interacts with the factor of hostility, which is specific to them. Association with delinquent peers recognized as a major risk factor and predictive for the self-revealed delinquency of teenagers in general does not intervene for these boys who perceive their pubertal development late, compared to the others. The delinquency of teenagers with a delayed PPT cannot be explained by the factors that are considered in the general population, their social functioning and the socialization of these teenagers with delayed puberty is different from that of the other teenagers, as is their implication in delinquency, which is not explained by a kind of socialization with delinquent peers. These results confirm the importance of integrating the puberty variable into research on delinquency, but also at the level of intervention. [less ▲]

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See detailChanges in pubertal timing: Past views, Recast issues
Bourguignon, Jean-Pierre ULg; Domine, Françoise; Glowacz, Fabienne ULg et al

in Bourguignon, Jean-Pierre; Carel, Jean-Claude; Christen, Yves (Eds.) Brain Crosstalk in Puberty in Adolescence (2015)

Abstract The aim of this article is to review some common opinions on changes in pubertal timing and shed new light both on the indicators used in assessing pubertal timing and the underlying mechanisms ... [more ▼]

Abstract The aim of this article is to review some common opinions on changes in pubertal timing and shed new light both on the indicators used in assessing pubertal timing and the underlying mechanisms. While emphasis is usually on advancement in timing of female puberty, it appears that timing also changes in males, both towards earliness for the initial pubertal stages and towards lateness for the final stages. Such findings suggest that the environmental influences on pubertal timing are more complex than initially thought. Moreover, self-evaluated pubertal timing versus peers provides information that is not always consistent with observations at physical examination, suggesting that both perspectives should be considered, especially when studying the correlation between pubertal timing and psychosocial aspects. The mechanisms of changes in pubertal timing may involve both central neuroendocrine control and peripheral effects in tissues targeted by gonadal steroids. Though energy availability is certainly a clue to the mechanism of pubertal development, changes in the control of both energy balance and control of reproduction may vary under the influence of common determinants such as endocrine-disrupting chemicals. These effects can take place right before puberty as well as much earlier, during fetal and neonatal life. Finally, environmental factors can interact with genetic factors in determining changes in pubertal timing. Therefore, the variance in pubertal timing is no longer to be considered under the absolutely separate control of environmental and genetic determinants.  [less ▲]

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