Region-specific loss of zinc in the brain in pentylentetrazole-induced seizures and seizure susceptibility in zinc deficiency

Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52- 1 Yada, Shizuoka 422-8526, Japan.
Epilepsy Research (Impact Factor: 2.02). 08/2006; 70(1):41-8. DOI: 10.1016/j.eplepsyres.2006.03.002
Source: PubMed


The hippocampus is thought to be an epileptic focus in human temporal lobe epilepsy. Kainate-induced seizures decrease zinc concentrations in the hippocampus, which is also decreased in young mice fed a zinc-deficient diet for 4 weeks, and is enhanced by zinc deficiency. To understand zinc movement in the brain in epileptic seizures, zinc concentrations in the brain were measured in young mice after administration of pentylentetrazole, a GABAA receptor antagonist. Zinc concentration in the hippocampus and Timm's stain, with which histochemically reactive zinc in the presynaptic vesicle is detected, were decreased after the administration, suggesting that excessive excitation of zinc-containing glutamatergic neurons is induced in the hippocampus with pentylentetrazole. To clarify whether the decrease in zinc concentration in the hippocampus in zinc deficiency alter seizure susceptibility, furthermore, susceptibility to pentylentetrazole-induced seizures was examined in young mice fed the zinc-deficient diet for 4 weeks. The susceptibility, unlike susceptibility to kainate-induced seizures, was not appreciably enhanced by zinc deficiency. These results suggest that the decrease in zinc concentration in the hippocampus in zinc deficiency does not influence susceptibility to pentylentetrazole-induced seizures.

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    • "Variations in volume and architecture of the hippocampus have been observed in some brain diseases such as epilepsy, schizophrenia, mild cognitive impairment, and Alzheimer's disease (Scher et al. 2007). The hippocampus is thought to be an epileptic focus in human temporal lobe epilepsy (Takeda et al. 2006). "
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    • "Deux autres études menées en Italie et aux États-Unis, chez des enfants ayant une épilepsie pharmacorésistante ont montré qu'ils étaient à risque de malnutrition, mais aucune étude similaire n'a été réalisée jusqu'à présent chez les épileptiques non pharmacorésistants dans les pays développés [10] [16]. Chez l'animal, de nombreuses études ont été menées [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32]. Leur but était de mettre en évidence le rôle éventuel de la dénutrition dans la survenue de crises d'épilepsie en explorant différentes pistes comme une carence en protéines ou en certains micronutriments. "
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