Publications by authors named "Anne-Sophie Villegier"

The fifth generation (5G) network is currently being worldwide spread out, raising questions about the potential impact of this new technology, particularly on immature organisms. The current study aimed to investigate the effects of daily 5G electromagnetic field (EMF) perinatal exposure on the neurodevelopment of rats. The exposure level was set to the limit of whole-body public exposure defined by the International Commission on Non-Ionizing Radiation Protection.

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The World Health Organization and the French Health Safety Agency (ANSES) recognize that the expressed pain and suffering of electromagnetic field hypersensitivity syndrome (EHS) people are a lived reality requiring daily life adaptations to cope. Mechanisms involving glutamatergic N-methyl d-aspartate (NMDA) receptors were not explored yet, despite their possible role in hypersensitivity to chemicals. Here, we hypothesized that radiofrequency electromagnetic field (RF-EMF) exposures may affect pain perception under a modulatory role played by the NMDA receptor.

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Background: Alzheimer's disease (AD) is the most common type of neurodegenerative disease leading to dementia. Several studies suggested that mobile phone radiofrequency electromagnetic field (RF-EMF) exposures modified AD memory deficits in rodent models.

Objective: Here we aimed to test the hypothesis that RF-EMF exposure may modify memory through corticosterone and oxidative stress in the Samaritan rat model of AD.

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Purpose: Gliomas are the most common cancer of the brain, with a poor prognosis in particular for glioblastoma. In 2014, a study suggested reduced survival in relation to latency of mobile phone use among glioblastoma patients. A joint epidemiological/experimental project to study effects of RF-EMF on tumor development and progression was established.

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Purpose: Glioblastoma is a malignant brain tumor which has one of the poorest prognosis. It is not clear if toxic environmental factors can influence its aggressiveness. Recently, it was suggested that brain cancer patients with heavy cell phone use showed reduced survival.

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Today, developmental intellectual disorders affect one out of six children in industrialised countries. Intensively used in agriculture, the neurotoxicant pesticide chlorpyrifos (CPF) is known for its environmental persistence and bioaccumulation. Its role has not yet been established in the aetiology of intellectual impairments.

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Exposure of pregnant women to radiofrequency (RF) devices raises questions on their possible health consequences for their progeny. We examined the hazard threshold of gestational RF on the progeny's glial homeostasis, sensory-motor gating, emotionality, and novelty seeking and tested whether maternal immune activation would increase RF toxicity. Pregnant dams were daily restrained with loop antennas adjoining the abdomen (fetus body specific absorption rates (SAR): 0, 0.

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The widespread mobile phone use raises concerns on the possible cerebral effects of radiofrequency electromagnetic fields (RF EMF). Reactive astrogliosis was reported in neuroanatomical structures of adaptive behaviors after a single RF EMF exposure at high specific absorption rate (SAR, 6 W/kg). Here, we aimed to assess if neuronal injury and functional impairments were related to high SAR-induced astrogliosis.

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The widespread use of mobile phones by adolescents raises concerns about possible health effects of radiofrequency electromagnetic fields (RF EMF 900 MHz) on the immature brain. Neuro-development is a period of particular sensitivity to repeated environmental challenges such as pro-inflammatory insults. Here, we used rats to assess whether astrocyte reactivity, perception, and emotionality were affected by RF EMF exposures during adolescence.

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The increasing use of mobile phones by aging people raises issues about the effects of radiofrequency electromagnetic fields (RF-EMF) on the aging central nervous system. Here, we tested if mobile phone RF-EMF exposures could exacerbate senescence-typical neurobiological deficits. Thus, aged (22-24 months) and young (4-6 months) adult male rats were subjected to head RF-EMF exposures (900 MHz, specific absorption rate (SAR) of 6 W/kg, 45 min/day for 1 month in restraint rockets).

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Background: P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) play a critical role in keeping neurotoxic substances from entering the brain. We and others have previously reported an impact of inflammation on the regulation of adult blood-brain barrier (BBB) efflux transporters. However, studies in children have not been done.

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Our current knowledge about drug transporters in the maturational brain is very limited. In this study, we provide a comprehensive overview of the expression and activity profile of P-glycoprotein (P-gp), Breast Cancer Resistance Protein (bcrp), Organic Anion Transporter 3 (oat3), and Transporting Peptide 1a4 (oatp1a4) transporters during blood-brain barrier (BBB) maturation. Gene and protein expressions of the analyzed transporters increase as the brain matures, with no variation in their activity for P-gp and bcrp, while the transport activity of oat3 and oatp1a4 increases during brain maturation from preterm up to adulthood.

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The widespread use of mobile phones raises the question of the effects of electromagnetic fields (EMF, 900 MHz) on the brain. Previous studies reported increased levels of the glial fibrillary acidic protein (GFAP) in the rat's brain after a single exposure to 900 MHz global system for mobile (GSM) signal, suggesting a potential inflammatory process. While this result was obtained in adult rats, no data is currently available in older animals.

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The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences.

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Article Synopsis
  • α5 GABA(A) receptors and α7 nACh receptors play a key role in cognitive functions in the hippocampus, influencing neuron activity and synchronization.
  • The research explores if using two allosteric modulators concurrently can enhance cognition by showing that combined application leads to long-term potentiation (LTP) in rat hippocampal neurons.
  • The compound 522-054 is designed to target both receptors simultaneously and demonstrates improved cognitive performance in behavioral tests, suggesting its potential therapeutic use in cognitive impairments.
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Although nicotine is generally considered to be the main psychoactive component of tobacco, growing evidence highlights the importance of nonnicotine compounds in smoking reinforcement. Monoamine oxidase (MAO) inhibition is a major consequence of smoking and MAO inhibitors, such as tranylcypromine, increase nicotine reinforcement. Tranylcypromine has multiple pharmacological effects, increasing monoamine release for a few hours immediately after its administration and blocking MAO activity for several days.

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Earlier studies reported exacerbated locomotor response to stress and tranylcypromine in β2 nicotinic acetylcholine receptor (nAChR) knockout (KO) mice. This study aimed to further assess the role of β2 and coexpressed nAChR subunits in the brain (α4, α6 and α7) to control monoamine-mediated locomotor response, that is, response to novelty, saline, nicotine with tranylcypromine pretreatment, cocaine, d-amphetamine and morphine treatments. Results show that β2 KO mice were hyperreactive to novelty, cocaine and morphine.

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Rationale: Epidemiological studies have demonstrated a comorbidity of smoking with depression and anxiety, particularly during adolescence. However, few animal studies have considered possible synergistic interactions between nicotine and other tobacco smoke constituents, such as monoamine oxidase (MAO) inhibitors, in the regulation of mood.

Objectives: The aim of the study was to test the hypothesis that nicotine combined with the irreversible MAO inhibitor, tranylcypromine, will differentially affect depression- and anxiety-related behaviors in adolescent and adult rats.

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Rationale: The mechanisms mediating tobacco addiction remain elusive. Nicotine, the psychoactive component in tobacco, is generally believed to be the main cause of reward and addiction. However, tobacco smoke contains thousands of constituents, some of which may interact with nicotine to enhance reward.

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Tobacco use has one of the highest rates of addiction of any abused drug. Paradoxically, in animal models, nicotine appears to be a weak reinforcer. We report here that the inhibition of monoamine oxidase (MAO), a major effect of tobacco smoke, increases the reinforcing effect of nicotine.

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Although nicotine is generally considered as the main compound responsible for addictive properties of tobacco, some experimental data indicate that nicotine does not exhibit all the characteristics of other substances of misuse such as psychostimulants and opiates. For example, nicotine generally fails to induce locomotor response in mice and self-administration of nicotine is difficult to obtain in rats. We have shown recently that a pretreatment with mixed irreversible monoamine oxidase inhibitors (MAOIs), such as tranylcypromine, triggers a locomotor response to nicotine in mice and induces a robust self-administration of nicotine in rats.

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Nicotine has been shown to activate stress-related brain nuclei, including the paraventricular nucleus of the hypothalamus (PVN) and the central nucleus of the amygdala (CEA), through complex mechanisms involving direct and indirect pathways. To determine the neurochemical identities of rat brain neurons which are activated by a low dose (0.175 mg/kg) of nicotine given 30 minutes before sacrifice, we have used single- and double-label in situ hybridization.

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Article Synopsis
  • Nicotine alone doesn't fully act like other addictive drugs, showing limited effects on movement in lab animals compared to known stimulants and opiates.
  • Recent experiments found that combining nicotine with certain monoamine oxidase inhibitors (MAOIs) can lead to increased locomotor activity, indicating a potential synergy between these substances.
  • Specifically, in mice with the beta2-nicotinic receptor knocked out, the locomotor response to this combination was absent, which highlights the importance of this receptor in nicotine's rewarding effects when paired with MAOIs.
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Drugs of abuse, such as D-amphetamine or nicotine, are generally considered as acting through an increased release of dopamine in a subcortical structure, the nucleus accumbens, thus inducing locomotor hyperactivity in rats. Following repeated treatments, the same drugs induce a progressive increase in locomotor response called behavioral sensitization. This process has been suggested to play a role in the acquisition and maintenance of addictive behaviors.

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Recent experiments have shown that mice lacking the alpha1b-adrenergic receptor (alpha1b-AR KO) are less responsive to the locomotor hyperactivity induced by psychostimulants, such as D-amphetamine or cocaine, than their wild-type littermates (WT). These findings suggested that psychostimulants induce locomotor hyperactivity not only because they increase dopamine (DA) transmission, but also because they release norepinephrine (NE). To test whether NE release could increase DA-mediated locomotor hyperactivity, rats were treated with GBR 12783 (10 mg/kg), a specific inhibitor of the DA transporter, and NE release was enhanced with dexefaroxan (0.

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