Quantitative analysis of granule cell axons and climbing fiber afferents in the turtle cerebellar cortex.
Quantitative analysis of granule cell axons and climbing fiber afferents in the turtle cerebellar cortex.
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龟小脑皮质中颗粒细胞轴突和攀爬纤维传入的定量分析。
DOI：
10.1007/s00429-004-0423-0
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Ariel,M
中科院分区：
文献类型：
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作者：
Tolbert,DL;Conoyer,B;Ariel,M
海龟小脑皮质是一个单一的平面片的灰质，大大有利于定量分析的生物素化葡聚糖胺标记的颗粒细胞和橄榄小脑轴突和Nissl染色的颗粒和浦肯野神经元。平均而言，上行颗粒细胞轴突比其平行纤维分支相对较粗（平均值±SD：分别为0.84±0.17和0.64±0.12 µm）。突触前接触的部位Numerousen pasantsstrom，存在于上行和平行的纤维颗粒细胞轴突上。上行轴突上的纤维直径（1.82±0.34 µm，n=52）略大于平行纤维上的纤维直径（1.43±0.24 µm，n=430）。此外，每单位长度（100 µm），上行轴突（11.2±4.2）上的神经元比平行纤维（9.7±4.2）上的神经元更多。来自上行轴突的每个平行纤维分支约1.5 mm长。橄榄小脑攀援纤维轴突跟随浦肯野细胞的高度曲折的树突在最内部的15-20%的分子层。攀缘纤维表现出相对较少的迁移。攀爬纤维乔木的空间周长（面积）从前（1797 µm2）到后（3090 µm2）增加了72%，从内侧（1690 µm2）到外侧（3450 µm2）增加了104%。颗粒细胞轴突上的大小和间距的差异表明，上行轴突可能有一个功能上更显着的影响有限数量的径向覆盖浦肯野细胞的兴奋性比单一的平行纤维与多个正交排列的浦肯野细胞树突的接触。攀援纤维在最内层分子层中的空间限制性分布、很少的纤维束和不同的末端乔木区是个谜。然而，这些发现为未来的光学成像和电生理实验提供了重要的解剖信息。
The turtle cerebellar cortex is a single flat sheet of gray matter that greatly facilitates quantitative analysis of biotylinated dextran amine labeled granule cell and olivocerebellar axons and Nissl-stained granule and Purkinje neurons. On average, ascending granule cell axons are relatively thicker than their parallel fiber branches (mean±SD: 0.84±0.17 vs 0.64±0.12 µm, respectively). Numerousen passantswellings, the site of presynaptic contact, were present on both ascending and parallel fiber granule cell axons. The swellings on ascending axons (1.82±0.34 µm,n=52) were slightly larger than on parallel fibers (1.43±0.24 µm,n=430). In addition, per unit length (100 µm) there were more swellings on ascending axons (11.2±4.2) than on parallel fibers (9.7±4.2). Each parallel fiber branch from an ascending axon is approximately 1.5 mm long. Olivocerebellar climbing fiber axons followed the highly tortuous dendrites of Purkinje cells in the inner most 15–20% of the molecular layer. Climbing fibers displayed relatively feweren passantswellings. The spatial perimeter of climbing fiber arbors (area) increased 72% from anteriorly (1797 µm2) to posteriorly (3090 µm2) and 104% from medially (1690 µm2) to laterally (3450 µm2). Differences in the size and spacing ofen passantswellings on granule cell axons suggest that ascending axons may have a functionally more significant impact on the excitability of a limited number of radially overlying Purkinje cells than the single contacts by parallel fiber with multiple orthogonally aligned Purkinje cell dendrites. The spatially restricted distribution of climbing fibers to the inner most molecular layer, the paucity ofen passantswellings, and different terminal arbor areas are enigmatic. Nevertheless, these finding provide important anatomical information for future optical imaging and electrophysiological experiments.