References of "Cornil, Charlotte"
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See detailActivation of estrogen receptor beta (ERb) by estrogens rapidly regulates male sexual motivation
Seredynski, Aurore; Ball, Gregory F.; Kelly, Martin J. et al

Conference (2013, September 13)

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See detailNeuro-estrogens and sexual behavior
Cornil, Charlotte ULg

Conference (2013, July 19)

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See detailNeuroestrogens Rapidly Regulate Sexual Motivation But Not Performance
Seredynski, Aurore ULg; Balthazart, Jacques ULg; Christophe, Virginie et al

in Journal of Neuroscience (2013), 33(1), 164-174

Estrogens exert pleiotropic effects on reproductive traits, which include differentiation and activation of reproductive behaviors and the control of the secretion of gonadotropins. Estrogens also ... [more ▼]

Estrogens exert pleiotropic effects on reproductive traits, which include differentiation and activation of reproductive behaviors and the control of the secretion of gonadotropins. Estrogens also profoundly affect non-reproductive traits, such as cognition and neuroprotection. These effects are usually attributed to nuclear receptor binding and subsequent regulation of target gene transcription. Estrogens also affect neuronal activity and cell-signaling pathways via faster, membrane-initiated events. How these two types of actions that operate in distinct timescales interact in the control of complex behavioral responses is poorly understood. Here, we show that the central administration of estradiol rapidly increases the expression of sexual motivation, as assessed by several measures of sexual motivation produced in response to the visual presentation of a female but not sexual performance in male Japanese quail. This effect is mimicked by membrane-impermeable analogs of estradiol, indicating that it is initiated at the cell membrane. Conversely, blocking the action of estrogens or their synthesis by a single intracerebroventricular injection of estrogen receptor antagonists or aromatase inhibitors, respectively, decreases sexual motivation within minutes without affecting performance. The same steroid has thus evolved complementary mechanisms to regulate different behavioral components (motivation vs performance) in distinct temporal domains (long- vs short-term) so that diverse reproductive activities can be properly coordinated to improve reproductive fitness. Given the pleiotropic effects exerted by estrogens, other responses controlled by these steroids might also depend on a slow genomic regulation of neuronal plasticity underlying behavioral activation and an acute control of motivation to engage in behavior. [less ▲]

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See detailFemale sexual and social behaviors are controlled by estrogens
de Bournonville, Catherine ULg; Ball, Gregory F; Balthazart, Jacques ULg et al

Poster (2013)

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See detailFemale sexual motivation is controlled by estrogens in quail
de Bournonville, Catherine ULg; Ball, Gregory F; Balthazart, Jacques ULg et al

Poster (2013)

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See detailLocal estradiol synthesis in the brain and its implication in male and female sexual motivation of Japanese quail
de Bournonville, Catherine ULg; Schmit, Mélanie; Ball, Gregory F et al

in Trabajos del Instituto Cajal (2013)

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See detailAre neuroestrogens implicated in sexual motivation? Development of experimental protocols.
de Bournonville, Catherine ULg; Schmit, Mélanie; Ball, Gregory F et al

Poster (2013)

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See detailRapid control of reproductive behaviour by locally synthesised oestrogens: focus on aromatase.
Cornil, Charlotte ULg; Seredynski, Aurore ULg; de Bournonville, Catherine ULg et al

in Journal of Neuroendocrinology (2013), 25(11), 1070-8

Oestrogens activate nucleus- and membrane-initiated signalling. Nucleus-initiated events control a wide array of physiological and behavioural responses. These effects generally take place within ... [more ▼]

Oestrogens activate nucleus- and membrane-initiated signalling. Nucleus-initiated events control a wide array of physiological and behavioural responses. These effects generally take place within relatively long periods of time (several hours to days). By contrast, membrane-initiated signalling affects a multitude of cellular functions in a much shorter timeframe (seconds to minutes). However, much less is known about their functional significance. Furthermore, the origin of the oestrogens able to trigger these acute effects is rarely examined. Finally, these two distinct types of oestrogenic actions have often been studied independently such that we do not exactly know how they cooperate to control the same response. The present review presents a synthesis of recent work carried out in our laboratory that aimed to address these issues in the context of the study of male sexual behaviour in Japanese quail, which is a considered as a suitable species for tackling these issues. The first section presents data indicating that 17b-oestradiol, or its membrane impermeable analogues, acutely enhances measures of male sexual motivation but does not affect copulatory behaviour. These effects depend on the activation of membrane-initiated events and local oestrogen production. The second part of this review discusses the regulation of brain oestrogen synthesis through post-translational modifications of the enzyme aromatase. Initially discovered in vitro, these rapid and reversible enzymatic modulations occur in vivo following variations in the social and environment context and therefore provide a mechanism of acute regulation of local oestrogen provision with a spatial and time resolution compatible with the rapid effects observed on male sexual behaviour. Finally, we discuss how these distinct modes of oestrogenic action (membrane- versus nucleus-initiated) acting in different time frames (short- versus long-term) interact to control different components (motivation versus performance) of the same behavioural response and improve reproductive fitness. [less ▲]

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See detailDistinct Neuroendocrine mechanisms control neural activity underlying sex differences in sexual motivation and performance
Balthazart, Jacques ULg; Corbisier de Méaultsart, Céline; Ball, Gregory et al

in European Journal of Neuroscience (2013), 37(5), 735-42

Sexual behavior can be usefully parsed into an appetitive and a consummatory component. Both appetitive and consummatory male-typical sexual behaviors (respectively, ASB and CSB) are activated in male ... [more ▼]

Sexual behavior can be usefully parsed into an appetitive and a consummatory component. Both appetitive and consummatory male-typical sexual behaviors (respectively, ASB and CSB) are activated in male Japanese quail by testosterone (T) acting in the medial preoptic nucleus (POM), but never observed in females. This sex difference is based on a demasculinization (= organizational effect) by estradiol during embryonic life for CSB, but a differential activation by T in adulthood for ASB. Males expressing rhythmic cloacal sphincter movements (RCSMs; a form of ASB) or allowed to copulate display increased Fos expression in POM. We investigated Fos brain responses in females exposed to behavioral tests after various endocrine treat- ments. T-treated females displayed RCSM, but never copulated when exposed to another female. Accordingly they showed an increased Fos expression in POM after ASB but not CSB tests. Females treated with the aromatase inhibitor Vorozole in ovo and T in adulthood displayed both male-typical ASB and CSB, and Fos expression in POM was increased after both types of tests. Thus, the neural circuit mediating ASB is present or can develop in both sexes, but is inactive in females unless they are exposed to exogenous T. In contrast, the neural mechanism mediating CSB is not normally present in females, but can be pre- served by blocking the embryonic production of estrogens. Overall these data confirm the difference in endocrine controls and probably neural mechanisms supporting ASB and CSB in quail, and highlight the complexity of mechanisms underlying sexual differentiation of behavior. [less ▲]

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See detailRAPID MODULATION OF AROMATASE ACTIVITY IN THE VERTEBRATE BRAIN
Charlier, Thierry; Cornil, Charlotte ULg; Balthazart, Jacques ULg

in Journal of Experimental Neuroscience (2013)

Numerous steroid hormones, including 17-estradiol (E2), activate rapid and transient cellular, physiological, and behavioral changes in addition to their well-described genomic effects. Aromatase is the ... [more ▼]

Numerous steroid hormones, including 17-estradiol (E2), activate rapid and transient cellular, physiological, and behavioral changes in addition to their well-described genomic effects. Aromatase is the key-limiting enzyme in the production of estrogens, and the rapid modulation of this enzymatic activity could produce rapid changes in local E2 concentrations. The mechanisms that might mediate such rapid enzymatic changes are not fully understood but are currently under intense scrutiny. Recent studies in our laboratory indicate that brain aromatase activity is rapidly inhibited by an increase in intracellular calcium concentration resulting from potassium- induced depolarization or from the activation of glutamatergic receptors. Phosphorylating conditions also reduce aromatase activity within minutes, and this inhibition is blocked by the addition of multiple protein kinase inhibitors. This rapid modulation of aromatase activity by phosphorylating conditions is a general mechanism observed in different cell types and tissues derived from a variety of spe- cies, including human aromatase expressed in various cell lines. Phosphorylation processes affect aromatase itself and do not involve changes in aromatase protein concentration. The control of aromatase activity by multiple kinases suggests that several amino acids must be concomitantly phosphorylated to modify enzymatic activity but site-directed mutagenesis of several amino acids alone or in combination has not to date revealed the identity of the targeted residue(s). Altogether, the phosphorylation processes affecting aro- matase activity provide a new general mechanism by which the concentration of estrogens can be rapidly altered in the brain. [less ▲]

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See detailNeurochemical control of rapid stress-induced changes in brain aromatase activity
Dickens, Molly; Cornil, Charlotte ULg; Balthazart, Jacques ULg

in Journal of Neuroendocrinology (2013), 25(4), 329-39

In the male brain, the medial preoptic nucleus (POM) is known to be a critical relay for the activation of sexual behaviour, with the aromatisation of testosterone into 17b-oestradiol (E2) playing a key ... [more ▼]

In the male brain, the medial preoptic nucleus (POM) is known to be a critical relay for the activation of sexual behaviour, with the aromatisation of testosterone into 17b-oestradiol (E2) playing a key role. Acute stress has been shown to differentially modulate the aromatase enzyme in this and other brain nuclei in a sex-specific manner. In POM specifically, stress induces increases in aromatase activity (AA) that are both rapid and reversible. How the physiological processes initiated during an acute stress response mediate sex- and nuclei- specific changes in AA and which stress response hormones are involved remains to be determined. By examining the relative effects of corticosterone (CORT), arginine vasotocin (AVT, the avian homologue to arginine vasopressin) and corticotrophin-releasing factor (CRF), the present study aimed to define the hormone profile regulating stress-induced increases in AA in the POM. We found that CORT, AVT and CRF all appear to play some role in these changes in the male brain. In addition, these effects occur in a targeted manner, such that modulation of the enzyme by these hormones only occurs in the POM rather than in all aromatase-expressing nuclei. Similarly, in the female brain, the experimental effects were restricted to the POM but only CRF was capable of inducing the stress-like increases in AA. These data further demonstrate the high degree of specificity (nuclei-, sex- and hormone-specific effects) in this system, highlighting the complexity of the stress–aromatase link and suggesting modes through which the nongenomic modulation of this enzyme can result in targeted, rapid changes in local oestrogen concentrations. [less ▲]

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See detailDynamic changes in brain aromatase activity following sexual interactions in males: Where, when and why?
de Bournonville, Catherine ULg; Dickens, Molly J.; Ball, Gregory F. et al

in Psychoneuroendocrinology (2013), 38(6), 789-99

It is increasingly recognized that estrogens produce rapid and transient effects at many neural sites ultimately impacting physiological and behavioral endpoints. The ability of estrogens to acutely ... [more ▼]

It is increasingly recognized that estrogens produce rapid and transient effects at many neural sites ultimately impacting physiological and behavioral endpoints. The ability of estrogens to acutely regulate cellular processes implies that their concentration should also be rapidly fine-tuned. Accordingly, rapid changes in the catalytic activity of aromatase, the limiting enzyme for estrogen synthesis, have been identified that could serve as a regulatory mechanism of local estrogen concentrations. However, the precise anatomical localization, time-course, triggering stimuli and functional significance of these enzymatic changes in vivo are not well understood. To address these issues as to where, when and why aromatase activity (AA) rapidly changes after sexual interactions, AA was assayed in six populations of aromatase-expressing cells microdissected from the brain of male quail that experienced varying durations of visual exposure to or copulation with a female. Sexual interactions resulted in a rapid AA inhibition. This inhibition occurred in specific brain regions (including the medial preoptic nucleus), in a context-dependent fashion and time-scale suggestive of post-translational modifications of the enzyme. Interestingly, the enzymatic fluctuations occurring in the preoptic area followed rather than preceded copulation and were tied specifically to the female's presence. This pattern of enzymatic changes suggests that rapid estrogen effects are important during the motivational phase of the behavior to trigger physiological events essential to activate mate search and copulation. [less ▲]

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See detailBrain-derived estrogens rapidly control sexual behavior in Japanese quail
Cornil, Charlotte ULg

Conference (2012, August 25)

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See detailDynamic and region specific changes in estrogen production induced by reproductive stimuli.
de Bournonville, Catherine ULg; Dickens, Molly J; Ball, Gregory F et al

Poster (2012, May 04)

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See detailRegion- and context-specific rapid changes in brain aromatase activity following social interactions
de Bournonville, Catherine ULg; Dickens, Molly J; Ball, Gregory F et al

Poster (2012)

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See detailCellular mechanisms controlling rapid changes in brain aromatase activity
Charlier, Thierry; Cornil, Charlotte ULg; Ball, Gregory et al

in Balthazart, Jacques; Ball, Gregory (Eds.) Brain aromatase, estrogens and behavior (2012)

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See detailRapid modulation of aromatase activity by social and environmental stimuli in quail
Cornil, Charlotte ULg; Dickens, Molly; BAll, Gregory et al

in Balthazart, Jacques; Ball, Gregory (Eds.) Brain aromatase, estrogens and behavior (2012)

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See detailRapid control of male typical behaviors by brain-derived estrogens
Cornil, Charlotte ULg; Ball, Gregory F; Balthazart, Jacques ULg

in Frontiers in Neuroendocrinology (2012)

Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance ... [more ▼]

Beside their genomic mode of action, estrogens also activate a variety of cellular signaling pathways through non-genomic mechanisms. Until recently, little was known regarding the functional significance of such actions in males and the mechanism that control local estrogen concentration with a spatial and time resolution compatible with these non-genomic actions had rarely been examined. Here, we review evidence that estrogens rapidly modulate a variety of behaviors in male vertebrates. Then, we present in vitro work supporting the existence of a control mechanism of local brain estrogen synthesis by aromatase along with in vivo evidence that rapid changes in aromatase activity also occur in a region-specific manner in response to changes in the social or environmental context. Finally, we suggest that the brain estrogen provision may also play a significant role in females. Together these data bolster the hypothesis that brain-derived estrogens should be considered as neuromodulators. [less ▲]

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See detailAcute and Specific Modulation of Presynaptic Aromatization in the Vertebrate Brain
Cornil, Charlotte ULg; Leung, Cary H.; Pletcher, Eric R. et al

in Endocrinology (2012), 153(6), 2562-7

Estrogens affect a diversity of peripheral and central physiological endpoints. Traditionally, estrogens were thought to be peripherally derived transcription regulators (i.e. slow acting). More recently ... [more ▼]

Estrogens affect a diversity of peripheral and central physiological endpoints. Traditionally, estrogens were thought to be peripherally derived transcription regulators (i.e. slow acting). More recently, we have learned that estrogens are also synthesized in neuronal cell bodies and synaptic terminals and have potent membrane effects, which modulate brain function. However, the mechanisms that control local steroid concentrations in a temporal and spatial resolution compatible with their acute actions are poorly understood. Here, using differential centrifugation followed by enzymatic assay, we provide evidence that estrogen synthesis within synaptosomes can be modulated more dramatically by phosphorylating conditions, relative to microsomes. This is the first demonstration of a rapid mechanism that may alter steroid concentrations within the synapse and may represent a potential mechanism for the acute control of neurophysiology and behavior. [less ▲]

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