Induction of neuronal cell death by neurotoxin factors

Using histochemical analysis (NADPH-diaphorase, Fluoro-Jade В dye and bisbenzimide 33342 Hoechst) we studied the influence of intraperitoneal administration of nicotine, kainic acid and combination of both these substances on hippocampal neurons and their changes. In experiments, 18- 25- and 35-day-old male rats of the Wistar strain were used. 30 minutes prior to the kainic acid application (10 mg/kg), animals were pre-treated with 1 mg/kg of nicotine. After 2 days, the animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia. Cryostat sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the CA1 and CA3 areas of the hippocampus, in the dorsal and ventral blades of the dentate gyrus and in the hilus of the dentate gyrus. Fluoro-Jade В positive cells were examined, in the same areas, to elucidate possibly neurodegeneration. Results have shown that nicotine administration brings about the increase of the density of NADPH-diaphorase positive neurons in CA1 and CA3 areas of the hippocampus and in the hilus of the dentate gyrus in 18-day-old animals, in 25-dayold animals in CA3 area of the hippocampus, hilus of the dentate gyrus and in the vevrtal blade of the dentate gyrus, in 35-day-old animals only in the CA3 area of the..