A rat model of repeated seizures induced by pentylenetetrazol at different maturational stages and the role of NF-?B in the pathogenesis of epilepsy / 中国病理生理杂志

ABSTRACT

AIM: To observe histopathologic changes and NF-?B expression in hippocampus in neonatal and matural rats after repeated seizures, and to explore the role of NF-?B in the pathogenesis of epilepsy in premature brain of rats. METHODS: Neonatal rats and mature rats were divided into 2 experimental groups at 10 days and 60 days after birth (P10 and P60). Convulsions were induced by repeated injection of pentylenetetrazol (PTZ) intraperitoneally for first 5 days. The animals in control group were injected with NS at the same volume in the same conditions. The neurons in CA1, CA3, dentate granule (DG), as well as in hilar were counted by thionin staining, in order to observe the profile of the necrosis and apoptosis. NF-?B expression was examined by immunohistochemistry assay. Timm's method of silver sulfide staining was adopted to observe the mossy fiber sprouting. RESULTS: (1) In immature rats (10 days old), neurons in CA1, CA3 and hilar demonstrated no differences from controls, whereas adult rats (P60) had a significant decrease in number of neurons in CA1 and CA3 (8.22?1.88, 5.62?1.68 vs 6.31?1.50, 3.62?1.40). In adult rats, neurons in dentate granule showed no differences with controls, whereas immature rats with daily seizures had a significant increase (23.25?3.06 vs 16.25?1.58). (2) There was prominent sprouting in the CA3 stratum pyramidal layer in all experimental rats after 5 daily seizures, regardless of the age. However, the degree of sprouting was significantly different between the two experimental groups (3.25?1.03 vs 1.50?0.92, P