Résumé
Today, about half of the world's population, even at a very young age, owns microwaveproducing mobile phones. As mobile phones are held in close proximity to the head, the microwaves emitted may exert many effects on the brain. This study aimed to evaluate the effects of long-term exposure to mobile phone emissions on the thalamic neurons and the integrity of its blood barrier. This study also aimed to investigate whether ascorbic acid could ameliorate microwave-induced thalamic changes. Forty adult male albino rats were used; they were divided into four equal groups. Group I served as a control group. In group II, rats were exposed to 0.043-0.135 W/kg for 42 days [4 h/day in the light]. The microwave radiation was produced by a mobile test phone [model NOKIA 3110]. Rats of group III were subjected to mobile waves as in group II and they concomitantly received oral ascorbic acid at a dose of 250 mg/kg/day. Group IV received ascorbic acid only. The thalamic neurons of wave-exposed animals showed significant morphological necrotic changes. Some appeared markedly vacuolated ; others were irregular in shape, with densely stained nuclei. Ultrastructurally, the cytoplasm of some neurons showed prominent cytoplasmic vacuolization. A significant decrease in the mean area percentage of tight junction protein occludin expression in thalamic microvessels was also detected. In contrast, sections obtained from rats of group III showed a significant improvement of the microwave-produced changes but never reverted to the same state as the controls. Chronic microwave exposure could have a marked effect on the thalamic neurons and its blood barrier. Administration of ascorbic acid resulted in a significant improvement, but it was not sufficient to gain a normal histological appearance