Valerie Simonneaux

Valerie Simonneaux
French National Centre for Scientific Research | CNRS · Institut des Neurosciences Cellulaires et Intégratives

About

170
Publications
17,836
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6,678
Citations
Citations since 2016
54 Research Items
2528 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400

Publications

Publications (170)
Article
Objectif Chez les mammifères femelles, la survenue du pic préovulatoire de LH dépend de la combinaison d’une œstradiolémie suffisante et d’un signal circadien qui permet la synchronisation du pic avec la fin de la période de repos, en fin de phase folliculaire. Le moment de l’occurrence du pic de LH étant crucial pour assurer une ovulation optimale...
Article
Synchronization of mammalian breeding activity to the annual change of photoperiod and environmental conditions is of utmost importance for individual survival and species perpetuation. Since the early 60s, when the central role of melatonin in this adaptive process was demonstrated, our comprehension of the mechanisms through which light regulates...
Article
Reproduction is a key biological function requiring a precise synchronization with annual and daily cues to cope with environmental fluctuations. Therefore, humans and animals have developed well-conserved photoneuroendocrine pathways to integrate and process circadian and seasonal light signals within the hypothalamic-pituitary-gonadal axis. Howev...
Article
In female mammals, reproductive senescence is a complex process involving progressive ovarian dysfunction, associated with altered central control of the hypothalamic-pituitary-gonadal axis and desynchronization of the circadian system. The objective of this study was to investigate age-dependent changes in the daily regulation of Arg-Phe amide-rel...
Article
Introduction En France, le travail posté concerne environ 20 % de la population active avec une prévalence croissante chez les femmes. Ce décalage horaire chronique altère le métabolisme et la reproduction via des mécanismes neuroendocriniens essentiellement analysés dans des études sur des rongeurs nocturnes mâles. Notre objectif est de mettre au...
Article
Full-text available
Kisspeptin (Kp) and (Arg)(Phe) related peptide 3 (RFRP-3) are two RF-amides acting in the hypothalamus to control reproduction. In the past 10 years, it has become clear that, apart from their role in reproductive physiology, both neuropeptides are also involved in the control of food intake, as well as glucose and energy metabolism. To investigate...
Article
Full-text available
Female reproductive success relies on proper integration of circadian- and ovarian- signals to the hypothalamic-pituitary-gonadal axis in order to synchronize the preovulatory LH surge at the end of the ovarian follicular stage with the onset of the main active period. In this study, we used a combination of neuroanatomical and electrophysiological...
Article
This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the arti...
Article
Full-text available
Background Hibernation is a physiological and behavioural adaptation that permits survival during periods of reduced food availability and extreme environmental temperatures. This is achieved through cycles of metabolic depression and reduced body temperature (torpor) and rewarming (arousal). Rewarming from torpor is achieved through the activation...
Article
Mammals adapt to seasons using a neuroendocrine calendar defined by the photoperiodic change in the nighttime melatonin production. Under short photoperiod, melatonin inhibits the pars tuberalis production of TSHβ, which, in turn, acts on tanycytes to regulate the deiodinase 2/3 balance resulting in a finely tuned seasonal control of the intra-hypo...
Preprint
Full-text available
Background Hibernation is a physiological and behavioural adaptation that permits survival during periods of reduced food availability and extreme environmental temperatures. This is achieved through cycles of metabolic depression and reduced body temperature (torpor) and rewarming (arousal). Rewarming from torpor is achieved through the activation...
Article
In addition to its regulatory role in luteinizing hormone secretion, RFamide related peptide 3 (RFRP3) has also been reported to modulate food intake in several mammalian species. Djungarian hamsters (Phodopus sungorus), like other seasonal mammals, display a remarkable inhibition of RFRP3 expression in winter short day conditions, associated with...
Article
In female mammals, cycles in reproductive function depend both on the biological clock synchronized to the light/dark cycle, and a balance between the negative and positive feedbacks of estradiol whose concentration varies during oocyte maturation. In women, studies report that chronodisruptive environments such as shiftwork, may impair fertility a...
Article
Mus musculus molossinus (MSM) is a wild-derived mouse strain which maintains the ability to synthesize melatonin in patterns reflecting the ambient photoperiod. The objective of this study was to characterize the effects of photoperiodic variation on metabolic and reproductive traits, and the related changes in pituitary-hypothalamic gene expressio...
Article
In female mammals, reproductive senescence is a complex process involving progressive ovarian dysfunction associated with an altered central control of the hypothalamic-pituitary axis. The objective of this study was to compare the longitudinal change in preovulatory luteinizing hormone (LH) secretion as well as estrous cycle in individual C57BL/6...
Article
The dromedary camel (Camelus dromedarius) is a desert mammal whose cycles in reproductive activity ensure that the offspring's birth and weaning coincide with periods of abundant food resources and favourable climate conditions. In this study, we assessed whether kisspeptin (Kp) and arginine-phenylalanine (RF)-amide related peptide-3 (RFRP-3), two...
Article
Full-text available
Adaptation of reproductive activity to environmental changes is essential for breeding success and offspring survival. In mammals, the reproductive system displays regular cycles of activation and inactivation which are synchronized with seasonal and/or daily rhythms in environmental factors, notably light intensity and duration. Thus, most species...
Article
Many animals exhibit remarkable metabolic and reproductive adaptations to seasonal changes in their environment. When day length shortens, Djungarian hamsters (Phodopus sungorus) reduce their body weight and inhibit their reproductive activity, whereas the opposite occurs in springtime. These physiological adaptations are considered to depend on ph...
Article
Reproduction, like many other biological functions, exhibits marked daily and seasonal rhythms in order to anticipate and adapt breeding activity to environmental challenges. In recent years, studies investigating the neuroendocrine mechanisms driving rhythms in reproduction have unveiled the pivotal role of hypothalamic neurons expressing kisspept...
Article
Rhythms in female reproduction, notably the timing of the preovulatory luteinizing hormone surge at the rest/activity transition, are critical to ensure that ovulation coincides with oocyte maturation and optimal sexual arousal. This fine tuning involves principally estradiol feedback as an indicator of oocyte maturation, and the master circadian c...
Article
Full-text available
Hibernation is an exceptional physiological response to a hostile environment, characterized by a seasonal period of torpor cycles involving dramatic reductions of body temperature and metabolism, and arousal back to normothermia. As the mechanisms regulating hibernation are still poorly understood, here we analysed the expression of genes involved...
Article
De nos jours, l’organisme est soumis à d’importantes variations circadiennes (notamment lors de travail posté), induisant chez les femmes une baisse de la fertilité. Chez des souris femelles C57BL/6J, 2 protocoles d’altération du cycle lumière/obscurité ont été imposés : 1) un décalage unique d’avance puis de retard de phase de 10 h et 2) un décala...
Article
Full-text available
Cerebrospinal fluid (CSF) is a fluidic part of the brain’s microenvironment that isolates the brain from the rest of the body. CSF dilutes metabolites from neuronal activities and removes them from the brain. Its production and resorption are regulated dynamically and are central to maintaining brain homeostasis. We discovered that the major CSF so...
Article
Full-text available
For many years, it was of interest to identify the sequences encoding the two melatonin receptors (MT₁ and MT₂) from various species. After publishing the basic molecular characterization of the human, rat, mouse, sheep, and platypus MT₁, MT₂, or Mel1c receptors, we began cloning the genes from other animals, such as birds, bats, and vipers. The go...
Article
Full-text available
The dromedary camel (Camelus dromedarius), a well-adapted desert mammal, is a seasonal breeder whose sexual activity occurs during the winter and spring. These periods coincide with food resources and climate conditions are favorable for offspring's survival. The mechanisms involved in the control of this seasonality however still need to be elucid...
Article
Adaptation of biological rhythms to a seasonal environment in circannual mammals is achieved via the synchronization of intrinsic circannual rhythms to the external year by photoperiod. In mammals, the photoperiodic information is integrated to seasonal physiology via the pineal hormone melatonin regulation of pars tuberalis (PT) TSHβ expression an...
Article
Full-text available
Melatonin is a neurohormone produced in both animals and plants. It binds at least three G-protein-coupled receptors: MT1 and MT2, and Mel1cGPR. Mammalian GPR50 evolved from the reptilian/avian Mel1c and lost its capacity to bind melatonin in all the therian mammal species that have been tested. In order to determine if binding is lost in the oldes...
Data
As per the new policy from Plos One, the raw data are available from the supporting information tables. They are counter listings, formatted to give the individual numbers used to calculate all the saturation curves and affinities reported in the present paper. The plates are all arranged the same ways: Saturation: The 3 first columns are used for...
Data
Platypus Mel1c gene in comparison with chicken and the clawed frog. Structure of Mel1c in platypus. The entire gene is 34,831 bp in length, where ~30,000 bp intron separates two exons: exon 1 is 184 bp long and exon 2 is 866 bp long. Every 5000 bp are labeled. B) Protein alignment of Mel1c from platypus (O. anatinus), chicken (G. gallus) and the cl...
Chapter
In temperate climates, most species are submitted to pronounced annual changes in temperature, light exposure and food availability. Because reproduction requires large energy expenditure, the timing of birth and weaning of offspring has evolved to coincide with a period of maximal food availability. To achieve this, breeding activity needs to be p...
Article
Full-text available
In seasonal rodents, reproduction is activated by a long photoperiod. Furthermore, maintaining an inhibitory short photoperiod for over 20 weeks triggers a spontaneous reactivation of the gonadotropic axis called photorefractoriness. Photoactivation is proposed to involve melatonin, hypothalamic thyroid hormones (TH) and (Arg) (Phe)-amide peptides....
Article
Female ovulation depends on a surge in circulating luteinizing hormone (LH) which occurs at the end of the resting period and requests high circulating estradiol. This fine tuning involves both an estradiol feedback as an indicator of oocyte maturation, and the master circadian clock of the suprachiasmatic nuclei as an indicator of the time of the...
Article
Many animals synchronize their reproductive activity with the seasons to optimize their offspring's survival. This synchronization involves switching on and off their gonadotropic axis. Ever since their discovery as key regulators of GnRH neurons, the hypothalamic RF-amide peptides kisspeptin and RFRP have been a major focus of research on the seas...
Article
Significance In mammals, long-term programming of offspring physiology occurring before birth has effects persisting into adulthood. Appropriate programming allows environmental preadaptation, while inappropriate programming has deleterious health and fitness consequences. To define the mechanistic pathways underlying maternal programming, this stu...
Article
Full-text available
emale mammals are classified into spontaneous and induced ovulators based on the mechanism eliciting ovulation. Ovulation in spontaneous species (e.g., human, sheep, cattle, horse, pigs, and most rodents) occurs at regular intervals and depends upon the circulating estradiol. However, in induced ovulators (e.g., rabbits, ferrets, cats, and camelids...
Article
Full-text available
The central circadian pacemaker, the suprachiasmatic nucleus (SCN), encodes day length information by mechanisms that are not well understood. Here, we report that genetic ablation of miR-132/212 alters entrainment to different day lengths and non-24 hr day-night cycles, as well as photoperiodic regulation of Period2 expression in the SCN. SCN neur...
Article
Although opiates represent the most effective analgesics, their use in chronic treatments is associated with numerous side effects including the development of pain hypersensitivity and analgesic tolerance. We recently identified a novel orally active neuropeptide FF (NPFF) receptor antagonist, RF313, which efficiently prevents the development of f...
Article
In females, reproductive activity relies on proper integration of daily and environmental changes as well as cyclic sex-steroid feedback. This study aimed at investigating the role of the hypothalamic Arg-Phe amide-related peptide (RFRP)-3 in the daily and seasonal control of reproductive activity in female Syrian hamsters, by analyzing the RFRP sy...
Article
Full-text available
Jerboas are wild rodents exhibiting exceptional adaptation to their desert environment. Under harsh autumn conditions, they shut down reproduction, increase body weight and hibernate, while during spring they become sexually active even under negative energy-balance. We recently reported that these rhythms are associated with synchronized changes i...
Research
Full-text available
Parutions : La coordination des activités de reproduction et du métabolisme est essentielle, particulièrement chez les individus soumis à de larges variations de leur environnement. Des chercheurs de l'Institut des neurosciences cellulaires et intégratives et du Laboratoire de neuroendocrinologie et environnement nutritionnel et climatique de l'Uni...
Article
Objectif Analyser les effets de décalages horaires chroniques sur le cycle estrien et la sécrétion de LH. Matériel et méthodes Des femelles C57BL/6, initialement exposées à un cycle lumière/obscurité (LD) stable, ont été soumises à deux décalages horaires ; G1 : une avance de phase de 10 h pendant 3 mois puis un retard de phase de 10 h pendant 3 m...
Article
Full-text available
A series of dipeptides were designed as potential agonists of the human KiSS1-derived peptide receptor (hGPR54). While the sequence Arg-Trp-NH2 was the most efficient in terms of affinity, we established a convergent synthetic strategy to optimize the N terminus. Using two successive Sonogashira cross-coupling reactions on a solid-supported peptide...
Book
Full-text available
https://www.anses.fr/fr/system/files/AP2011SA0088Ra.pdf
Article
Full-text available
Seasonal control of reproduction is critical for the perpetuation of species living in temperate zones that display major changes in climatic environment and availability of food resources. In mammals, seasonal cues are mainly provided by the annual change in the 24h light/dark ratio (i.e. photoperiod), which is translated into the nocturnal produc...
Article
Jerboa (Jaculus orientalis) is a semi-desert rodent displaying strong seasonal variations in biological functions in order to survive harsh conditions. When environmental conditions become unfavorable in early autumn, it shuts down its reproductive axis, increases its body weight and finally hibernates. In spring, the jerboa displays opposite regul...
Chapter
Most mammals use photoperiod to synchronize their breeding season, so that young are raised during the spring and summer months. The pineal hormone melatonin is the major endocrine message used to relay photoperiodic information to the reproductive axis. This chapter first discusses the ecological context for seasonal breeding and the pivotal role...
Article
Full-text available
Rhythms in female reproduction are critical to insure that timing of ovulation coincides with oocyte maturation and optimal sexual arousal. This fine tuning of female reproduction involves both the estradiol feedback as an indicator of oocyte maturation, and the master circadian clock of the suprachiasmatic nuclei (SCN) as an indicator of the time...
Article
RF-(Arg-Phe) related peptides (RFRP-1 and -3) are considered to play a role in the seasonal regulation of reproduction however the peptides effect depends on species and gender. This study aimed at comparing the RFRP system in male and female Syrian hamsters in long and short photoperiod to investigate the neuroanatomical basis of these differentia...
Article
The kisspeptin (Kp) neurons in the anteroventral periventricular nucleus (AVPV) are essential for the preovulatory luteinizing hormone (LH) surge, which is gated by circulating estradiol (E2) and the time of day. We investigated whether AVPV Kp neurons in intact female mice may be the site where both E2 and daily signals are integrated, and whether...
Article
Full-text available
When food availability is restricted, animals adjust their behavior according to the timing of food access. Most rodents, such as rats and mice, and a wide number of other animals express before timed food access a bout of activity, defined as food-anticipatory activity (FAA). One notable exception amongst rodents is the Syrian hamster, a photoperi...
Article
Animals living in temperate zones anticipate seasonal environmental changes to adapt their biological functions, especially reproduction and metabolism. Two main physiological mechanisms have evolved for this adaptation: intrinsic long-term timing mechanisms with an oscillating period of approximately 1 year, driven by a circannual clock [1], and s...
Article
In many species, sexual activity varies on a seasonal basis. Kisspeptin (Kp), a hypothalamic neuropeptide acting as a strong activator of GnRH neurones, plays a critical role in this adaptive process. Recent studies reported that two other neuropeptides, namely neurokinin B (NKB) and dynorphin (DYN), are co-expressed with Kp (and therefore termed K...
Article
Kiss1 mRNA and its corresponding peptide products, kisspeptins, are expressed in two restricted brain areas of rodents, the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (ARC). The concentration of mature kisspeptins may not directly correlate with Kiss1 mRNA levels, because mRNA translation and/or posttranslational modificat...
Article
In mammals, melatonin is the pivotal messenger synchronizing biological functions, notably reproductive activity, with annual daylength changes. Recently, two major findings clarified melatonin's mode of action. First, melatonin controls the production of thyroid stimulating hormone (TSH) by the pars tuberalis of the adenohypophysis. This TSH regul...
Article
Full-text available
Seasonal mammals use the photoperiodic variation in the nocturnal production of the pineal hormone melatonin to synchronize their reproductive activity with seasons. In rodents, the (SD) short day profile of melatonin secretion has long been proven to inhibit reproductive activity. Lately, we demonstrated that melatonin regulates the expression of...
Article
Full-text available
At temperate latitudes many mammals and birds show internally timed, long-term changes in seasonal physiology, synchronised to the seasons by changing day length (photoperiod). Photoperiodic control of thyroid hormone levels in the hypothalamus dictates the timing. This is effected through reciprocal regulation of thyroid hormone deiodinase gene ex...