Contrasting expression of Kv4.3, an A-type K+ channel, in migrating Purkinje cells and other post-migratory cerebellar neurons
Contrasting expression of Kv4.3, an A-type K+ channel, in migrating Purkinje cells and other post-migratory cerebellar neurons
复制标题
DOI：
10.1046/j.1460-9568.2003.02786.x
复制
发表时间：
2003-08-01
影响因子：
3.4
通讯作者：
Tsaur, ML
中科院分区：
文献类型：
--
作者：
Hsu, YH;Huang, HY;Tsaur, ML
Kv4.3是一种A型K+通道，是迄今为止已知的在哺乳动物小脑颗粒层中唯一显示出前后（A-P）区室化的通道分子。在成年大鼠小脑的后颗粒层而非前颗粒层中检测到了 Kv4.3 mRNA。为了进一步表征这种 A-P 区室化，我们在胚胎、出生后早期和成年阶段通过免疫组织化学检查了大鼠小脑中 Kv4.3 蛋白的表达。通过蛋白质印迹和免疫沉淀分析证实了 Kv4.3 抗体的特异性。在成年期，Kv4.3是从后颗粒细胞的体树突域中检测到的，在虚拟小叶VI中具有限制边界，横向延伸至半球小腿1 Ansiform小叶。在出生后早期，这种 A-P 模式首次出现在出生后第 8 天，此时大量颗粒细胞已迁移到后颗粒层并开始表达 Kv4.3。小脑迁移后神经元的体树突域中类似的 Kv4.3 表达也在篮细胞、星状细胞、GABA 能深层神经元的子集、Lugaro 细胞以及可能的深 Lugaro 细胞中观察到。然而，它们都没有表现出 A-P 区室化。引人注目的是，我们在几个具有中外侧区室化的迁移浦肯野细胞簇中发现了 Kv4.3。这些浦肯野细胞在完成迁移后不再表达 Kv4.3。通过对比迁移和迁移后神经元中的表达，我们的结果表明 Kv4.3 可能在小脑发育以及成熟小脑中发挥重要作用。
Kv4.3, an A-type K+ channel, is the only channel molecule showing anterior-posterior (A-P) compartmentalization in the granular layer of mammalian cerebellum known so far. Kv4.3 mRNA has been detected from the posterior but not anterior granular layer in adult rat cerebellum. To characterize this A-P compartmentalization further, we examined Kv4.3 protein expression in rat cerebellum by immunohistochemistry at the embryonic, early postnatal and adult stages. Specificity of the Kv4.3 antibody was confirmed by both Western blot and immunoprecipitation analysis. In adulthood, Kv4.3 was detected from the somatodendritic domain of posterior granule cells, with a restriction boundary in the vermal lobule VI extending laterally to the hemispheric crus 1 ansiform lobules. At the early postnatal stage, this A-P pattern first appeared on postnatal day 8, when significant numbers of granule cells had migrated into the posterior granular layer and started to express Kv4.3. Similar Kv4.3 expression in the somatodendritic domain of post-migratory neurons in the cerebellum was also observed in basket cells, stellate cells, a subset of GABAergic deep neurons, Lugaro cells and, probably, deep Lugaro cells. However, none of them showed A-P compartmentalization. Strikingly, we found Kv4.3 in several clusters of migrating Purkinje cells with mediolateral compartmentalization. These Purkinje cells no longer expressed Kv4.3 after completing the migration. By contrasting the expression in migrating and post-migratory neurons, our results suggest that Kv4.3 may play an important role in the development of cerebellum, as well as in the mature cerebellum.