EARLY DENDRITIC DEVELOPMENT OF PURKINJE-CELLS IN THE RAT CEREBELLUM - A LIGHT AND ELECTRON-MICROSCOPIC STUDY USING AXONAL TRACING IN INVITRO SLICES
EARLY DENDRITIC DEVELOPMENT OF PURKINJE-CELLS IN THE RAT CEREBELLUM - A LIGHT AND ELECTRON-MICROSCOPIC STUDY USING AXONAL TRACING IN INVITRO SLICES
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DOI：
10.1016/0165-3806(91)90213-3
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发表时间：
1991-12-17
期刊：
影响因子：
--
通讯作者：
SOTELO, C
中科院分区：
文献类型：
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作者：
ARMENGOL, JA;SOTELO, C
从胚胎第19天（E19）到出生后第6天（P6），用辣根过氧化物酶（HRP）“体外”轴突示踪法分析了浦肯野细胞树突状动脉形成的早期阶段。 这些阶段包括从双极浦肯野细胞的过渡，在其迁移结束时，与定向树突的星状细胞的阶段。 迁移后浦肯野细胞在皮质板表现出不完善的双极形状，这里称为“简单梭形”细胞。 它们构成了绝大多数标记细胞，直到P0，此后它们的数量减少，直到P4。 由于新的初级树突从顶极出现，但也从基底和侧面的细胞体的连续生长的结果，浦肯野细胞进入“复杂的梭形”阶段，其峰值由P1和P6慢慢消失。 “复杂梭形”细胞的消失是一个强烈的退行性过程的结果，长树突的吸收或收缩在P3达到最大值。 我们称这一阶段为：浦肯野细胞与“退行性萎缩”树突。 这种退化标志着星状细胞阶段的开始，其特征是在各个方向出现的较短的体周突起的爆炸性生长。 到P6，几乎所有标记的浦肯野细胞都达到了这个阶段。 标记的浦肯野细胞的超微结构研究表明，梭形细胞的瞬时树突具有成熟树突的所有细胞学特征，特别是细胞骨架成分（微管）和游离多聚核糖体。 更重要的是，未知来源的轴突终端建立了一些，不断存在的，成熟的突触接触的树突状轴和棘突从P0，最早的研究年龄。 在进入星状细胞期的浦肯野细胞上其频率增加。 我们的研究结果强调，双极迁移后浦肯野细胞转化为星状细胞阶段的结果从一个复杂的级联交替的创造性和破坏性的过程，发生在平行的形成和退化的成熟突触接触，重塑树突状乔木和身份不明的传入输入之间。 浦肯野细胞，在所有不同的过渡阶段，并排存在于相同的叶区域，至少直到P4，并接受类似的突触输入的特遣队。 这表明树突重塑不是由突触输入驱动的，而是服从导致浦肯野细胞呈现其单细胞层构型的神经相互作用，或者取决于浦肯野细胞出生日期的内部时钟，或者这两种机制之间的相互作用。
The early stages in the formation of Purkinje cell dendritic arbors have been analyzed using the horseradish peroxidase (HRP) 'in vitro' axonal tracing method, from embryonic day 19 (E19) to postnatal day 6 (P6). These stages comprise the transition from the bipolar Purkinje cell, at the end of its migration, to the phase of stellate cell with disoriented dendrites. Postmigratory Purkinje cells in the cortical plate exhibit poorly elaborated bipolar shapes, here named 'simple-fusiform' cells. They constitute the vast majority of labeled cells up to P0, and thereafter they decrease in number until P4. As a result of continuous outgrowth of new primary dendrites emerging from the apical pole but also from the basal and lateral aspects of the cell bodies, the Purkinje cells enter the 'complex-fusiform' phase, which peaks by P1 and slowly disappears by P6. The disappearance of 'complex-fusiform' cells is the result of an intense regressive process with resorption or retraction of the long dendrites that reaches a maximum by P3. We have called this stage: the Purkinje cell with 'regressive-atrophic' dendrites. This regression marks the initiation of the phase of the stellate cell, characterized by the explosive outgrowth of shorter perisomatic protrusions emerging in all directions. By P6, almost all the labeled Purkinje cells have attained this phase. The ultrastructural study of the labeled Purkinje cells has revealed that the transient dendrites of the fusiform cells have all the cytologic features of mature dendrites, particularly cytoskeletal elements microtubules) and free polyribosomes. More importantly, axon terminals of unknown origin establish a few, constantly present, mature-like synaptic contacts on the dendritic shafts and spinous protrusions from P0, the earliest studied age. Their frequency increases on the Purkinje cells which enter the phase of stellate cell. Our results emphasize that the transformation of bipolar postmigratory Purkinje cells into the stellate cell stage results from a complex cascade of alternating creative and destructive processes, taking place in parallel with the formation and regression of mature synaptic contacts, between the remodelling dendritic arbors and unidentified afferent inputs. Purkinje cells, in all the different transitional stages, are present side by side in the same folial regions, at least until P4, and receive a similar contingent of synaptic input. This indicates that the dendritic remodelling is not driven by the synaptic inputs, but obeys either neural interactions that lead Purkinje cells to assume their monocellular layer configuration, or an internal clock depending on the Purkinje cell birthdate, or an interplay between these two kinds of mechanisms.