Serapide M F, Pantó M R, Parenti R, Zappalá A, Cicirata F
Dipartimento di Scienze Fisiologiche, Universita di Catania, 95125 Catania, Italy.
J Comp Neurol. 2001 Feb 19;430(4):471-84. doi: 10.1002/1096-9861(20010219)430:4<471::aid-cne1044>3.0.co;2-g.
This study revealed a sagittal zonal pattern of projections to the cerebellar cortex after hydraulic or iontophoretic injections of anterograde tracers (tritiated leucine, wheat germ agglutinin-horseradish peroxidase, or biotinylated dextrane amine) in the basilar pontine nuclei of Wistar rats. The zonal pattern of projection was observed only after injections of small size, whereas large injections labeled diffusely wide areas of the cerebellar cortex, masking the zonal projection because the fusion of contiguous stripes. Diverging projections to discrete sets of sagittal stripes in the two sides of the cerebellar cortex arose from single injections. The stripes of fiber terminals were sharply delimited on both sides by areas, interstripes, either virtually void of labeling or with a much lower density of labeling. Thus, the areas of the cerebellar cortex were parceled in sets of sagittal compartments, stripes and interstripes, by the pontine projections. Up to five compartments (three stripes and two interstripes) were observed in the paraflocculus, in the copula pyramidis, and in vermal lobule IX. Up to nine compartments (five stripes and four interstripes) were found in the crus I, the lobulus simplex, the paramedian lobule, and vermal lobules VI-VIII. Up to seven compartments (four stripes and three interstripes) were found in the crus II. Single injections into the basilar pontine nuclei usually labeled symmetric areas of the cerebellar cortex, which, in some cases, showed similar number of stripes. When this was not the case, the stripes were usually more numerous in the contralateral than in the ipsilateral side. All areas of the cerebellar cortex were projected upon, with zonation patterns from different regions of the basilar pontine nuclei. The projections of the basilar pontine nuclei to the cerebellar cortex were arranged according to a fixed pattern specific for each cortical area, independently of the number of stripes labeled within. The mean width of the stripes visualized in the single cortical areas of different rats was similar, despite the different size of the injections. The length of the stripes ranged widely in the various areas of different rats. The data collected in this study are consistent with the idea that all the mossy afferents to the cerebellar cortex are arranged with a zonal pattern.
本研究揭示了在Wistar大鼠脑桥基底部核团中经液压或离子电渗法注射顺行示踪剂（氚标记亮氨酸、小麦胚凝集素-辣根过氧化物酶或生物素化葡聚糖胺）后，投射至小脑皮质的矢状带模式。仅在注射小剂量示踪剂后观察到投射的带状模式，而大剂量注射则标记了小脑皮质广泛的弥散区域，由于相邻条纹融合而掩盖了带状投射。单次注射可产生向小脑皮质两侧离散矢状条纹组的发散投射。纤维终末条纹在两侧由几乎无标记或标记密度低得多的区域（条纹间区）清晰界定。因此，脑桥投射将小脑皮质区域划分为矢状区室、条纹和条纹间区组。在旁绒球、锥体连合和蚓叶IX中观察到多达5个区室（3条条纹和2个条纹间区）。在小脑脚I、单小叶、旁正中小叶和蚓叶VI-VIII中发现多达9个区室（5条条纹和4个条纹间区）。在小脑脚II中发现多达7个区室（4条条纹和3个条纹间区）。单次注射到脑桥基底部核团通常标记小脑皮质的对称区域，在某些情况下，两侧条纹数量相似。当情况并非如此时，对侧条纹通常比同侧更多。小脑皮质的所有区域均有投射，来自脑桥基底部核团不同区域的投射具有分区模式。脑桥基底部核团向小脑皮质的投射根据每个皮质区域特有的固定模式排列，与所标记条纹的数量无关。尽管注射剂量不同，但不同大鼠单个皮质区域中可见条纹的平均宽度相似。不同大鼠各区域中条纹的长度范围差异很大。本研究收集的数据与小脑皮质所有苔藓纤维传入按带状模式排列的观点一致。
