猫骶髓后连合核的细胞构筑学

THE CYTOARCHITECTURE OF DORSAL COMMISSURE NUCLEUS OF THE SACRAL SPINAL CORD IN CAT

采用Nissl和Golgi染色技术、电镜技术,对描后连合核(DCN)进行了细胞构筑学研究。在T_10～S_1节段Ⅵ层的内侧部紧靠背索处,可以辨认出一个细胞形态有特征的核团。在S_(1～2)节段,随着灰质后连合的扩大,此核团向腹内方移动,形成位于中线背外侧的两个椭圆形核团;S_3～Co_1节段融合,形成一个底向中央管、尖朝向背索的三角形核团。此核团内的细胞以中、小型为主,偶见较大的神经元。Golgi阳性神经元主要有3种类型,即60％为小三角形神经元,30％为梭形神经元,10％为卵圆形或不规则神经元。电镜下大多数神经元内细胞器丰富,核膜均有深浅不等的内陷现象,在核膜内陷所形成的通道内,可见游离核糖体及大量囊泡。DCN中的突触有轴-树、轴-轴和轴-体突触,分别占89％、6％和5％, 还可见到一些连续性突触、轴棘突触和嵴突触。

The Nissl and Golgi staining methods and electron microscopy were u(?)o investigate the architecture of dorsal commissure nucleus (DCN) of the sacral spinal cord in cat. A morphologically specific nucleus could be identified in the medial part of the lamina Ⅵ of dorsal horn. The nucleus located beside the dorsal funiculus at the lumbar level and gradually moved toward the midline of the dorsal gray commissure in the ventromedial direction as the dorsal gray commissure enlarged at the segments S_(1-2) and two ellipsoid nuclei was formed at the two sides of the midline. A large triangular nucleus was gradually formed by fusion of the two nuclei at S_3-Co_1. Golgi stain positive neurons could be classified into three types: (1) small-triangular neurons (60%); (2) fusiform neurons (30%); (3) oval and irregular neurons (10%). The cell organells of most neurons were plentiful. The cell nucleus was irregular and often with deep invaginations. A large number of free ribosomes and saccules could be found in the canals formed by the nuclear invagination. There were axo-dentritic, axo-axonic, axo-somatic synaptic contacts in the DCN with percentages of 89%, 6%, and 5% respectively. The serial synapse, axo-spinous synapse and crest synapses could also be found.