Distribution of external cuneate nucleus afferents to the cerebellum: II. Topographical distribution and zonal pattern‐an experimental study with radioactive tracers in the cat
Distribution of external cuneate nucleus afferents to the cerebellum: II. Topographical distribution and zonal pattern‐an experimental study with radioactive tracers in the cat
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小脑外楔形核传入神经的分布：II 的地形分布和带状模式——放射性示踪剂在猫中的实验研究
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
J. Courville
中科院分区：
文献类型：
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作者：
L. Jasmin;J. Courville
使用少量氚化亮氨酸注射和放射自显影方法来证明从楔形外核（NCE）的限制部分到小脑的传出信号。参考 NCE 中初级肌肉传入的分布来分析注射部位。在横向截面上，银沉积物形成纵向带，在某些区域，纵向带堆积在一起并标记颗粒层的整个表面；在其他部分，它们被空的纵向带分开。纵向沉积物在体尾方向上不连续。根据纵向带的分布，II-VI 小叶被描述为 14 个区域，I、VIII 小叶和旁正中小叶中识别出 6 个区域。 NCE 的传入按地形分布。接受轴肌和颈部肌肉的核区域主要投射到小叶 I-III 的边缘区域，以及小叶 VIII 和 IX 的部分。接收来自前肢肌肉的传入信号的区域优先将其纤维发送到小叶 V 的蚓部区域、小叶 IV-VI 的旁蚓部区域、小叶 VIII 和 IX 的部分以及旁正中小叶。这些分布在几个方面与小脑的体位图一致。然而，其他特征支持“马赛克”排列：来自 NCE 区域的传出信号分布在皮质的几个不同位置，来自核不同部分的传出信号也汇聚到邻近的皮质区域。
Small injections of tritiated leucine and the autoradiographic method were used to demonstrate efferents from restricted portions of the external cuneate nucleus (NCE) to the cerebellum. Sites of injection were analyzed by reference to the distribution of primary muscle afferents in NCE. On transverse sections, the silver deposits form longitudinal bands that, in certain regions, are packed together and label the entire surface of the granular layer; in other parts, they are separated by empty longitudinal bands. The longitudinal deposits are not continuous in the rostrocaudal direction. On the basis of the distribution of the longitudinal bands, 14 zones have been described for lobules II‐VI, and 6 zones were recognized in lobules I, VIII, and the paramedian lobule. Afferents from NCE are distributed topographically. Regions of the nucleus receiving axial and neck muscles project mainly to vermal regions of lobules I‐III, and to parts of lobules VIII and IX. Regions receiving afferents from forelimb muscles send their fibers preferentially to the vermian region of lobule V, to paravermian regions of lobules IV‐VI, to parts of lobules VIII and IX, and to the paramedian lobule. These distributions in several respects are in agreement with the somatotopical maps of the cerebellum. However, other features support a “mosaic” arrangement: efferents from a region of NCE are distributed over several distinct sites of the cortex and efferents from different parts of the nucleus also converge to neighboring cortical regions.