Malmierca M S, Blackstad T W, Osen K K, Karagülle T, Molowny R L
Department of Anatomy, University of Oslo, Norway.
J Comp Neurol. 1993 Jul 1;333(1):1-27. doi: 10.1002/cne.903330102.
The cellular basis for the laminar structure of the central nucleus of the inferior colliculus has been investigated by computer-assisted 3-D reconstruction of Golgi impregnated dendritic arbors, sampled from serial sections of resin embedded material of adult rat. Two types of flattened neurone, defined here as flat (F) and less flat (LF), are described as contributing to the pattern. The dendritic arbors of F neurones had a smaller absolute thickness (mean about 50 microns) and a denser arbor. They were strikingly parallel regionally and formed laminae mostly one cell thick. The laminae appeared to be separated by interlaminar compartments populated by the LF neurones. The arbors of the latter were thicker (mean about 100 microns) and less dense than those of the F neurones. The different density of the two types may, at least in part, be responsible for the corresponding difference in density of oriented dendrites within the laminae and interlaminar compartments. The orientation planes of F and LF arbors were roughly similar, but a consistent, slight difference in orientation between F and LF arbors is not excluded. Most of the F and LF arbors were elongated in parallel with the ventrolaterally to dorsomedially oriented long axis of the laminae. A few were instead oriented rostrocaudally or in intermediate directions. The interlaminar compartments appeared less distinct in the low than in the high frequency region. The latter region also differed from the former by having F neurones with a higher number of intermediate and terminal segments and a denser arbor. It is discussed whether the observed F and LF cells constitute two distinct cell types or are varieties of one type of neurone, with the morphological differences reflecting differences in location. Further characterization of the neurones on histochemical, hodological, and other criteria is required to settle this question.
通过对成年大鼠树脂包埋材料连续切片中高尔基浸染树突分支进行计算机辅助三维重建，研究了下丘中央核层状结构的细胞基础。本文描述了两种扁平神经元，分别定义为扁平（F）神经元和较不扁平（LF）神经元，它们构成了这种模式。F神经元的树突分支绝对厚度较小（平均约50微米）且分支更密集。它们在区域上显著平行，形成的层大多只有一个细胞厚。这些层似乎被LF神经元占据的层间区隔开。后者的树突分支比F神经元的更厚（平均约100微米）且密度更低。两种类型的不同密度可能至少部分地导致了层内和层间区定向树突密度的相应差异。F和LF树突分支的定向平面大致相似，但不排除F和LF树突分支在定向方面存在一致的细微差异。大多数F和LF树突分支与层的腹外侧到背内侧的长轴平行伸长。少数则是前后向或中间方向定向。层间区在低频区域比高频区域显得不那么明显。后一个区域与前一个区域的不同之处还在于，F神经元具有更多的中间段和终末段以及更密集的分支。文中讨论了观察到的F和LF细胞是构成两种不同的细胞类型，还是一种神经元的不同变体，其形态差异反映了位置差异。需要根据组织化学、神经束路学和其他标准对神经元进行进一步表征来解决这个问题。
