Release of zinc from the brain of El (epilepsy) mice during seizure induction

Brain distribution after i.v. injection of (ZnCl2)-Zn-65 into El mice, an a nimal model of genetically determined epilepsy, was studied by autoradiogra phy to study the utilization of zinc in the brain. The distribution of Zn-6 5 in the brain of El mice 6 days after injection was almost the same as tha t of ddY (normal) mice, suggesting that the uptake of zinc by the brain of El mice is normal. To study the movement of zinc in the brain in the course of seizure induction, the concentrations of Zn-65 in the brain of seizure- afflicted and untreated control El mice were compared 20 days after Zn-65 i njection. The concentration of Zn-65 in the brain of seized El mice was ove rall lower than that of control El mice; the concentration of Zn-65 was dec reased notably in the piriform cortex and amygdaloid nuclei complex during convulsion. These results suggest that the release of zinc from the El mous e brain is enhanced during convulsion. The decrease in actively functioning zinc in the brain may be associated with the increase in susceptibility to seizure in the El mouse. (C) 1999 Elsevier Science B.V. All rights reserve d.