三叉神经尾侧脊束核内神经元的超微结构

THE ULTRASTRUCTURE OF THE NEURON IN THE SPINAL CAUDAL TRIGEMINAL NUCLEUS

在电镜下观察小白鼠三叉神经尾侧脊束桉。小白鼠三叉神经尾侧脊束核分为带状亚核、胶状质亚陔与大细胞亚核。胶状质亚核神经元的超微结构最突出的特点是细胞小,呈椭圆形,核大围以一薄层细胞质,粗面内质网少而散在。某些神经元核仁近旁有核仁帽。大细胞亚核神经元的超微结构与胶状质亚核的神经元相比,其特点为:细胞中等大小,主要为多边形,细胞核较大,胞质中等量,核膜凹陷或褶入明显,褶入处附近的胞质内聚集较多的核糖体、线粒体及高尔基氏器;某些神经元核仁附近有形态不规则的核仁帽;胞质内散在有较多的粗面内质网(尼氏小体)、大量的游离核糖体及线粒体。胶状质亚核与大细胞亚核内某些神经元核膜的凹陷和褶入,可能表明神经细胞处于不同活动时期的动态过程,它也许提示与细胞质内蛋白质合成有关。

The ultrastructure of the neuron of the spinal caudal trigeminal nucleus in the mice were investigated with electron microscope.The results were as follows.The spinal caudal trigeminal nucleus is subdivided into the subnuclei zonalis,gelatinosus and magnocellularis.The subnucleus gelatinosus is principally composed of small neurons,which is characterized by a relatively large nucleus,a small amount of cytoplasm and a paucity of rough endoplasmic reticulum.The neuron possesses an oval nucleus.In some places the nuclear membrance displays infoldings or invaginations.The nucleoplasm contains an oval nucleolus and chromatin.The cytoplasm contains a small amcunt of rough endoplasmic reticulum,many free ribosomes,some mitochondria,Golgi apparatus and lysosomes.The subnucleus magnocellularis is mainly composed of polygonal neurons.The ultrastructural characteristics of the neuron are containing medium volume of cytoplasm and a large nucleus,and possessing a distinct invagination of the nuclear membrane,In the cytoplasm of the invagination,a large number of ribosomes,endoplasmic reticulum,mitochondria and Golgi apparatus are present.In addition,the cytoplasm contains Nissl bodies,ribosomes and mitochondria and lysosomes,vesicles and microtubules.