听源性惊厥易感大鼠惊厥和点燃后听觉核团内的c-fos表达

C FOS EXPRESSION IN THE AUDITORY NUCLEI AFTER SINGLE AND KINDLED SEIZURES IN AUDIOGENIC SEIZURES PRONE RATS

为探讨听源性惊厥点燃和听觉核团的关系，用免疫细胞化学方法结合体视学分析，研究了Ｗｉｓｔａｒ种系的听源性惊厥易感大鼠（Ｐ７７ＰＭＣ）惊厥和点燃后听觉核团内ｃ－ｆｏｓ表达的差异。结果显示：１．正常Ｗｉｓｔａｒ大鼠接受１次铃声刺激后，蜗神经核、外侧丘系背核、下丘和内侧膝状体内没有Ｆｏｓ标记细胞；２．Ｐ７７ＰＭＣ大鼠１次听源性惊厥后，上述听觉核团内可见广泛的Ｆｏｓ标记细胞，其分布具有区域差异；３．Ｐ７７ＰＭＣ大鼠被点燃后，听觉核团内的Ｆｏｓ标记细胞更多，标记强度更大，特别是在外侧丘系背核和下丘，Ｆｏｓ标记细胞的密度和强度均显著高于１次惊厥后（Ｐ＜０．０１）。在内侧膝状体腹侧核，点燃后Ｆｏｓ标记细胞密度显著增加（Ｐ＜０．０５）。在内侧膝状体背侧核和蜗神经背核，Ｆｏｓ标记细胞无显著变化（Ｐ＞０．０５）。本研究结果表明，听源性惊厥诱导的ｃ－ｆｏｓ表达反映了听觉核团内神经元的异常活动，这种异常的神经元活动可能是听源性惊厥点燃的基础。

In order to explore the relationship of audiogenic kindling and auditory nuclei, the present study investigated the difference of c fos expression in cochlear nucleus, dorsal nucleus of the lateral lemniscus, inferior colliculus and medial geniculate body (MGD) after single (AS) and kindled (KAS) audiogenic seizures in P77PMC rats (a strain of Wistar audiogenic seizures prone rats). Using immunocytochemistry and morphometry, we obtained the following results: (1) Fos labelled neurons were hardly detected in the auditory nuclei in normal Wistar rats exposed to the acoustic stimulus (106dB, 60s); (2) in AS rats, c fos expression were found in all of the examined auditory nuclei, and there was a regionally distinctive labelled neurons distribution; (3) in KAS rats, the pattern of c fos expression in the auditory nuclei was approximately similar to that in AS rats. As compared with AS rats, the density and intensity of labelled neurons significantly increased in dorsal nucleus of the lateral lemniscus and inferior colliculus ( P <0.01). The density, but not intensity of labelled neurons also increased in ventral nucleus of MGD ( P <0.05), however, the density and intensity of labelled neurons did not increase in dorsal nucleus of MGD and cochlear nucleus ( P >0.05) as compared with AS rats. These results show that c fos expression induced by audiogenic seizures represents the abnormal neuronal activity which is limited to auditory nuclei, and this abnormal activity may be the basis of audiogenic kindling.