González-Hernández T H, Meyer G, Ferres-Torres R
Department of Anatomy, Faculty of Medicine, University of La Laguna, Tenerife, Spain.
Neuroscience. 1989;30(1):127-41. doi: 10.1016/0306-4522(89)90359-x.
The development of neuronal morphology and laminar organization in the central nucleus of the inferior colliculus has been studied with the different Golgi methods in kittens and cats of 1 day-2 years of age. The different Golgi methods used allowed us to selectively visualize the axonal or dendritic component of the fibrodendritic laminae. The characteristic lamination of the central nucleus defined by the fiber system of the lateral lemniscus is already present at birth. The axonal component of the laminae is constituted by parallel condensations of varicose terminals, myelinated axons, and preterminal fibers, oriented from ventrolateral to dorsomedial. The laminae are smaller in the dorsolateral edge of the nucleus. Neurons are classified mainly on the basis of their dendritic trees and the axonal ramification patterns. Three main types are distinguished: spinous disk-shaped neurons, aspinous to sparsely spinous disk-shaped neurons, and large or giant multipolar neurons. Our results suggest that the basic structures of the central nucleus--neuronal types and lamination of the lemniscal fibers--are already established at birth. The different neuronal types can be distinguished from the first days of life according to the ramification pattern of dendritic and axonal arbors. The characteristics of the different cell types, such as the density and distribution of dendritic spines, and the presence of varicose dendritic branchlets, are recognizable from the second week. At the end of the first month, neurons display an adult-like morphology, although the density of dendritic spines is higher than in the adult. Our morphological data can be related to the development of response properties in the inferior colliculus.
利用不同的高尔基方法，对1日龄至2岁的小猫和猫的下丘中央核中神经元形态和分层组织的发育进行了研究。所使用的不同高尔基方法使我们能够选择性地观察纤维树突层的轴突或树突成分。由外侧丘系纤维系统定义的中央核的特征性分层在出生时就已存在。这些层的轴突成分由曲张终末、有髓轴突和终末前纤维的平行聚集构成，从腹外侧向背内侧排列。在核的背外侧边缘，这些层较小。神经元主要根据其树突树和轴突分支模式进行分类。区分出三种主要类型：棘状盘状神经元、无棘至稀疏棘状盘状神经元以及大型或巨型多极神经元。我们的结果表明，中央核的基本结构——神经元类型和丘系纤维的分层——在出生时就已确立。从出生后的头几天开始，就可以根据树突和轴突分支的模式区分不同的神经元类型。不同细胞类型的特征，如树突棘的密度和分布，以及曲张树突小分支的存在，从第二周开始就可以识别。在第一个月末，神经元呈现出类似成年的形态，尽管树突棘的密度高于成年期。我们的形态学数据可以与下丘反应特性的发育相关联。
