Study of the mechanisms of the persistence seizure susceptibility acquired in the developing periods in amygdaloid kindled rats

我们用杏仁核点燃大鼠研究了在发育期获得的原发性和继发性癫痫发生是否持续到成年期。当在40天和70天时建立初始点燃时，点燃的大鼠在对侧和同侧部位诱导第5阶段癫痫发作所需的刺激次数明显少于未刺激的对照组。当在14天大时建立初始点火时，点燃大鼠的同侧或对侧部位诱导第5期癫痫发作所需的刺激次数与未刺激的对照组没有显著差异。当在28天龄时建立初始点火时，在同侧部位观察到促进作用，但在对侧部位没有。这些结果表明，14天获得的原发性和继发性癫痫发生在成熟后都减少了，并且在发育期获得的癫痫易感性的持久性在原发部位比继发部位弱。为了阐明癫痫易感性持续存在的机制，我们（MTX）治疗大鼠改变了未成熟时期杏仁核体点燃的发展和发育期间癫痫易感性的持续存在。味精和甲氨蝶呤治疗都显著减少了14天幼犬达到第5阶段癫痫发作所需的刺激次数。当大鼠在70天龄时重新点燃时，MSG和MTX治疗的大鼠诱导第5期癫痫发作所需的刺激次数明显低于对照大鼠。这些结果表明，味精和MTX均能增强未成熟大鼠对点燃诱发癫痫的易感性，并且在未成熟时期获得的增强的癫痫易感性将持续到成熟。

We investigated whether the primary and secondary epileptogenesis acquired in developing periods persists into adulthood using amygdaloid kindling rats. When the initial kindling was established at age 40 and 70 days, the number of stimulations required to induce the first stage 5 seizure at the contralateral as well as ipsilateral sites was significantly fewer in kindled rats than in non-stimulated controls. When the initial kindling was established at age 14 days the number of stimulations required to induce the first stage 5 seizure at neither ipsilateral or contralateral site in kindled rats was not significantly different from that in non-stimulated controls. When the initial kindling was established at age 28 days, the facilitative effect was observed at the ipsilateral site, but not at the contralateral site. These results suggest that both the primary and secondary epileptogenesis acquired at age 14 days is diminished after maturation, and the persistence of seizure susceptibility acquired in the developing periods is weaker in the primary than secondary site.To clarify the mechanisms of the persistence of seizure susceptibility, we (MTX) treatments in rats modify the development of amygdaloid kindling in immature period and the persistence of seizure susceptibility during development. Both MSG and MTX treatments decreased significantly the number of stimulations required to reach the first stage 5 seizure in pups at age 14 days. When the rats were rekindled at age 70 days, the number of stimulations required to reinduce the first stage 5 seizure was significantly lower in rats treated with both MSG and MTX than that in control rats. These results suggest that the susceptibility to kindling-induced seizure in immature rats is enhanced with both MSG and MTX treatments, and that the enhanced seizure susceptibility acquired in immature period persists into maturity.