REINNERVATION OF CEREBELLAR PURKINJE-CELLS BY CLIMBING FIBERS SURVIVING A SUBTOTAL LESION OF THE INFERIOR OLIVE IN THE ADULT-RAT .1. DEVELOPMENT OF NEW COLLATERAL BRANCHES AND TERMINAL PLEXUSES
REINNERVATION OF CEREBELLAR PURKINJE-CELLS BY CLIMBING FIBERS SURVIVING A SUBTOTAL LESION OF THE INFERIOR OLIVE IN THE ADULT-RAT .1. DEVELOPMENT OF NEW COLLATERAL BRANCHES AND TERMINAL PLEXUSES
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DOI：
10.1002/cne.903080403
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发表时间：
1991-06-22
影响因子：
2.5
通讯作者：
STRATA, P
中科院分区：
文献类型：
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作者：
ROSSI, F;WIKLUND, L;STRATA, P
小脑攀缘纤维在下橄榄部次全损伤后通过侧枝发芽做出反应，新形成的分支能够重新支配邻近的去神经浦肯野细胞。 在本文中，我们使用菜豆白细胞凝集素（PHA-L）示踪技术来标记攀缘纤维，并在光学显微镜水平上详细研究其可塑性。 具体目标是研究其发芽的时间过程和形态方面，估计其生长程度，并将新形成的终末神经丛与正常攀爬纤维进行比较。腹膜内注射 3-乙酰吡啶诱导大多数橄榄神经元变性，这些神经元终止于小脑皮质中的攀爬纤维。 通常，少数神经元在下橄榄中存活。 在小脑皮质中发现了分散的幸存攀爬纤维，没有任何损伤的迹象。 损伤后三天，幸存的攀缘纤维已经发出侧枝，这些侧枝通过分子层延伸一段距离，并以许多静脉曲张和非常细的小枝结束。 7 天后，就可以识别新发育的乔木，这些乔木在分子层中以与正常攀缘纤维相同的方向生长。 在较长的存活时间内，广泛的末端乔木已经形成，双标记实验证实它们终止于浦肯野细胞的近端树突周围。 新形成的末端丛在所有基本方面都类似于正常的攀缘纤维。 此外，从1个月起，很明显，每根幸存的攀爬纤维都能够形成几个新的末端神经丛，重新支配许多邻近的浦肯野细胞。 这个过程的结果是在亲本树枝周围形成大簇的新形成的丛。 定量估计表明，单个幸存的攀缘纤维的神经支配范围可以增加六倍以上。结论是，橄榄体次全损伤中幸存的攀缘纤维能够广泛发芽、轴突生长，并形成新的末端丛，类似于正常的攀缘纤维。 先前的电生理学证据表明这种神经支配是有功能的。 发芽的橄榄轴突重新支配近端浦肯野细胞树突的高度特异性表明生长的纤维与其目标之间存在精确的相互作用。 因此，这个“同型”侧支萌芽和神经支配的例子可能为神经-靶点相互作用的研究提供一个有用的模型。
Cerebellar climbing fibres react by collateral sprouting after subtotal lesions of the inferior olive, and the newly formed branches are able to reinnervate neighbouring denervated Purkinje cells. In the present paper, we used the Phaseolus vulgaris leucoagglutinin (PHA-L) tracing technique to label the climbing fibres and study their plasticity in detail at the light microscopical level. The specific objectives were to study the time course and morphological aspects of their sprouting, to estimate their extent of growth, and to compare the newly formed terminal plexuses with normal climbing fibres.Intraperitoneal injection of 3-acetylpyridine induced degeneration of the majority of the olivary neurones, which terminate as climbing fibres in the cerebellar cortex. Regularly, small numbers of neurones survived in the inferior olive. In the cerebellar cortex scattered surviving climbing fibres were found, which were devoid of any sign of injury. Already 3 days after the lesion, surviving climbing fibres had emitted collateral branches, which elongated for some distance through the molecular layer and ended with a number of varicosities and very fine branchlets. By 7 days, it was possible to recognize new developing arbours which grew in the molecular layer with the same orientation as normal climbing fibres. At longer survival times, extensive terminal arbours had developed and double labelling experiments confirmed that they terminated around the proximal dendrites of Purkinje cells. The newly formed terminal plexuses resembled, in all essential aspects, normal climbing fibres. In addition, from 1 month onward, it was evident that every surviving climbing fibre was able to form several new terminal plexuses reinnervating a number of neighbouring Purkinje cells. The result of this process was the formation of large clusters of newly formed plexuses around the parental arborization. Quantitative estimates indicated that the domain of innervation of single surviving climbing fibres could be increased by more than six times.It is concluded that climbing fibres surviving a subtotal olivary lesion are capable of extensive sprouting, axonal growth, and formation of new terminal plexuses, which resemble normal climbing fibres. Previous electrophysiological evidence indicates that this reinnervation is functional. The high specificity with which sprouting olivary axons reinnervate the proximal Purkinje cell dendrites suggests the existence of precise interactions between the growing fibres and their target. This example of "homotypic" collateral sprouting and reinnervation may thus provide a useful model for the study of nerve-target interactions.