Schweitzer L
Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, KY 40292.
Brain Res Dev Brain Res. 1990 Oct 1;56(1):19-27. doi: 10.1016/0165-3806(90)90159-v.
Many studies suggest that the details of morphogenesis (e.g. the length and number of dendrites) are determined by factors extrinsic to the cell, while the basic form of the neuron (e.g. the shape of the soma and the placement of the primary dendritic trunks) is determined by intrinsic factors. The following study describes the development of the dendrites of fusiform cells in the dorsal cochlear nucleus of the hamster using Golgi-stained brains from hamsters of various ages. Two basic types of dendrites are described--apical and basal--which emanate from opposite ends of the cell body and differ in their morphology. A third type of dendrite that exits the cell laterally can create a deflection in the perimeter of the cell body altering its shape. The morphology of these dendrites is described and compared to the apical and basal dendrites. Segments of laterally extending dendrites that are near apical dendrites are qualitatively and quantitatively identical to apical dendrites (that is they branch frequently and are spine-laden) and the converse is true of the segments near basal dendrites. The results suggest that during development, whether a dendritic will be apical-like or basal-like is determined by the location of its distal segment. Thus, extrinsic factors influence the overall form of these neurons.
许多研究表明，形态发生的细节（如树突的长度和数量）由细胞外部因素决定，而神经元的基本形态（如胞体形状和初级树突干的位置）则由内在因素决定。以下研究利用不同年龄仓鼠经高尔基染色的大脑，描述了仓鼠背侧耳蜗核中梭形细胞树突的发育情况。研究描述了两种基本类型的树突——顶端树突和基底树突，它们从细胞体的相对两端发出，形态各异。第三种从细胞侧面发出的树突可使细胞体周边产生偏转，改变其形状。本文描述了这些树突的形态，并与顶端树突和基底树突进行了比较。靠近顶端树突的横向延伸树突段在定性和定量上与顶端树突相同（即它们频繁分支且布满棘突），靠近基底树突的树突段情况则相反。结果表明，在发育过程中，一个树突是顶端样还是基底样取决于其远端段的位置。因此，外部因素影响这些神经元的整体形态。
