Champs électromagnétiques et vulnérabilité cérébrale

Parmi les innovations récentes, la téléphonie mobile a connu une progression fulgurante. Une conséquence en est que les expositions aux champs électromagnétiques (CEM) apparaissent de plus en plus tôt au cours de la vie (lors de l’adolescence, voire dès l’enfance), ce qui suscite des questionnements quant à leurs effets potentiels sur la santé humaine, en particulier sur le cerveau. Le projet "INFLAREF" visait à tester l’hypothèse d’une interaction entre les radiofréquences et le système nerveux, lorsque celui-ci se trouve en état de vulnérabilité parce qu’il est en phase de développement ou en lien avec l’exposition à des agents agresseurs

Effets des RF sur le système nerveux central : sommeil, EEG, vascularisation, cognition

National audienceLa plupart des études cliniques avec des champs RF ont étudié les effets d'expositions caractéristiques des téléphones portables, habituellement au niveau de la tête, sur un certain nombre de paramètres physiologiques comprenant le sommeil, l'activité électrique du cerveau, la cognition, la vascularisation cérébrale et plus généralement les systèmes cardiovasculaire et endocrinien. La majorité des études ont été effectuées chez des adultes en bonne santé. Il apparaît maintenant important d'étudier les effets des champs RF chez les enfants et les adolescents, étant donné la connaissance croissante d'une maturation continue du cerveau jusqu'à un stade avancé de l'adolescence, et quelques études récentes ont été effectuées avec des écoliers. Plusieurs études ont également porté sur des adultes qui déclarent être" électrosensibles "

Effects of 900 MHz radiofrequency on corticosterone, emotional memory and neuroinflammation in middle-aged rats

International audienceThe 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. Since the transition from middle-age to senescence is highly dependent on environment and lifestyle, we studied the reactivity of middle-aged brains to EMF exposure. We assessed the effects of a single 15 min GSM exposure (900 MHz ; specific absorption rate (SAR)=6 W/kg) on GFAP expression in young adults (6 week-old) and middle-aged rats (12 month-old). Brain interleukin (IL)-1ß and IL-6, plasmatic levels of corticosterone (CORT), and emotional memory were also assessed. Our data indicated that, in contrast to previously published work, acute GSM exposure did not induce astrocyte activation. Our results showed an IL-1ß increase in the olfactory bulb and enhanced contextual emotional memory in GSM-exposed middle-aged rats, and increased plasmatic levels of CORT in GSMexposed young adults. Altogether, our data showed an age dependency of reactivity to GSM exposure in neuro-immunity, stress and behavioral parameters. Reproducing these effects and studying their mechanisms may allow a better understanding of mobile phone EMF effects on neurobiological parameters

Effets des radiofréquences sur le système nerveux central chez l'homme : EEG, sommeil, cognition, vascularisation

International audienceMost of clinical studies on radiofrequency electromagnetic fields (RF) were directed at mobile phone-related exposures, usually at the level of the head, at their effect on some physiological functions including sleep, brain electrical activity (EEG), cognitive processes, brain vascularisation, and more generally on the cardiovascular and endocrine systems. They were frequently carried out on healthy adults. Effects on the amplitude of EEG alpha waves, mainly during sleep, look reproducible. It would however be important to define more precisely whether and how the absence of electromagnetic disturbance between RF exposure and the recording systems is checked. No consensus arises about cognitive effects. Some effects on cerebral vascularisation need complementary work.La plupart des études cliniques avec des champs radiofréquences (RF) ont porté sur les effets d'expositions caractéristiques des téléphones portables, habituellement au niveau de la tête, sur un certain nombre de fonctions physiologiques comprenant le sommeil, l'activité électrique du cerveau (EEG), la cognition, la vascularisation cérébrale et, plus généralement, les systèmes cardiovasculaire et endocrinien. La majorité des études a été effectuée chez des adultes en bonne santé. L'effet décrit sur l'amplitude des ondes alpha de l'EEG, notamment pendant le sommeil, semble reproductible. Il semble cependant important de préciser si et comment l'absence d'interférence entre l'exposition RF et l'enregistrement est vérifiée. Il ne se dégage pas de consensus sur des effets cognitifs. Quelques effets décrits sur la vascularisation cérébrale nécessitent des études complémentaires

Effet des radiofréquences sur des modèles de vulnérabilité cérébrale : développement et neuro-inflammation

International audienceThe widespread exposure of radiofrequency electromagnetic fields (RF-EMF) devices raises questions on their possible health consequences on the immature brain. Neuro-development is a period of sensitivity to environmental challenges such as inflammatory insults. Here, we assessed whether sensorymotor gating, emotionality, and novelty seeking were affected by RF-EMF exposures in fetus or adolescent rats, and tested whether maternal immune activation or adolescent neuroinflammation would increase RF-EMF toxicity. Rats were daily exposed to RF-EMF with loop antennas adjoining the abdomen of pregnant females (fetus body specific absorption rates (SAR): 0, 0.7 or 2.6 W/kg) or the head of adolescents (brain SAR: 0, 1.5 or 6 W/kg). Our result indicated that novelty seeking at adolescence was reduced after gestational exposure at 2.6 W/kg. Maternal immune activation induced a SAR-dependent reduction of sensory-motor gating in adults and adolescent neuroinflammation elicited a SAR-dependent reduction of emotionality. These data support the fact that special attention is needed for protection of developing organisms from combined environmental exposures with RF-EMF.Les applications utilisant les champs électromagnétiques (CEM) se sont considérablement développées depuis plusieurs années. Quotidiennement, ces applications peuvent notamment fonctionner dans l’environnement rapproché des femmes enceintes ou être intensivement utilisées au niveau de la tête dès l’adolescence. Les organismes immatures sont susceptibles d’être fragilisés par des expositions combinées (à des agents infectieux par exemple), pertinentes d’un point de vue environnemental. Dans ce contexte, l’Ineris a réalisé des expériences visant à étudier si des CEM appliqués en prénatal ou à l’adolescence modifieraient à long terme l’homéostasie des cellules gliales et les capacités sensori-motrices, émotionnelles, et de recherche de nouveauté. De plus, l’hypothèse selon laquelle un état inflammatoire pourrait rendre ces organismes plus vulnérables en réponse aux CEM a été testée

Champs électromagnétiques et vulnérabilité cérébrale: Effet des champs électromagnétiques GSM sur des modèles de vulnérabilité cérébrale : développement et neuro-inflammation

Les expositions aux champs électromagnétiques apparaissent de plus en plus tôt au cours de la vie (lors de l’adolescence, voire dès l’enfance), ce qui suscite des questionnements quant à leurs effets potentiels sur la santé humaine, en particulier sur le cerveau. Le projet de recherche "INFLAREF" visait à tester l’hypothèse d’une interaction entre les radiofréquences et le système nerveux, lorsque celui‐ci se trouve en état de vulnérabilité parce qu’il est en phase de développement ou est exposé à des agents agresseurs

Caractérisation des effets d’un champ électromagnétique GSM sur des modèles de vulnérabilité cérébrale : développement, neuro-inflammation et hypersensibilité

International audienc

Effect of radiofrequency electromagnetic fields on in vivo C6 brain tumors in Wistar rats

Previous literature suggested that brain cancer patients with heavy cell phone use showed reduced survival. Here we aimed to test survival and tumor aggressiveness in the C6 cells glioblastoma model in Wistar rats subjected to controlled brain averaged specific absorption rate (BASAR) induced by radiofrequency electromagnetic field (RF-EMF) exposures. For the first time, BASARdependent effects were reported in vivo by the reduction of apoptosis and by the reduction of inflammation in the tumor micro-environment. In accordance with the literature, our data did not suggest any impact on survival or tumor volume. Further replication studies are needed to confirm these observations

Impact of cerebral radiofrequency exposures on oxidative stress and corticosterone in a rat model of Alzheimer's disease

Alzheimer´s diseases (AD) is the most common type of neurodegenerative disease leading to dementia. The cause of AD remains unknown, however several studies suggested that mobile phone radiofrequency electromagnetic fields (RF-EMF) exposures interacted with AD memory deficits in rodent models. Here we aimed to test the hypothesis that RF-EMF exposure may modify memory through corticosterone and oxidative stress in a rat model of AD. Long-Evans rats were healthy controls or AD models. AD rats received continuous intracerebroventricular infusion with ferrous sulphate, beta amyloid (βA) 1-42 peptide and buthionine-sufloximine (Lecanu, 2006). RF-EMF exposures were performed to the head for 1 month (5 days/week, 15 or 45 min/day in restraint) to mimic cell phone use. To look for hazard threshold, repeated exposures were set to reach high brain averaged specific absorption rates (BASAR): 1,5 W/Kg (15 min), 6 W/Kg (15 min) or 6 W/Kg (45 min). The sham group exposure was 0 W/kg (45 min). Endpoints were spatial memory in the radial maze, plasmatic corticosterone, heme oxygenase 1 (HO1) and neurofibrillary tangles. Results indicated that AD rats had increased thioflavine and HO1 staining, reduced memory performances and similar corticosterone level compared to healthy rats. In AD rats, reduced corticosterone and increased hippocampal HO1 staining were observed after the 6 W/kg 45 min exposure. There was no RF-EMF effect on memory and cortical HO1. In healthy rats, increased cortical HO1 staining was observed after the 6 W/kg 45 min exposure. There was no RF-EMF effect on memory, hippocampal HO1 staining or corticosterone. According to our data, neither AD nor healthy rats showed modified memory after RF-EMF exposures. Unlike healthy rats, AD rats showed higher hippocampal oxidative stress and reduced corticosterone after our highest BASAR exposures. This data may support the hypothesis of a specific fragility related to neurodegenerative disease towards RF-EMF exposures. Further studies should be performed to replicate this data

Neurobiological effects of repeated radiofrequency exposures in male senescent rats

International audienceThe 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). To assess senescence-typical neurobiological deficits, spatial memory, emotional memory, anxiety-related behavior, locomotor activity, interleukins (IL)-1 beta and 6, glial fibrillary acidic protein (GFAP) and corticosterone were measured. Aged rats presented deficits in spatial learning, exploration, anxiety-related behaviors, and increased hippocampal ILs and cortical IL-1 beta Results showed that senescence-typical neurobiological deficits were not modified by RF-EMF exposures. RF-EMF-exposed rats (young and aged adults pooled) had decreased anxiety-related behaviors in the elevated plus maze. This study which is the first to assess RF-EMF exposures during late aging did not support the hypothesis of a specific cerebral vulnerability to RF-EMF during senescence. More investigations using longer RF-EMF exposures should be performed to conclude regarding the inoffensiveness of RF-EMF exposures