大鼠脊髓前角运动细胞白质树突的电镜观察

在电镜下对未作标记及类霍乱原结合辣根过氧化物酶(CB-HRP)标记的大鼠脊髓运动细胞白质树突(WMD)进行观察,发现其全程上确有大量轴-树突触存在。突触小泡以清亮圆形和椭圆形为主,偶见有颗粒小泡与清亮小泡共存。此结果为脊髓运动细胞机能调节的旁侧回路假说提供了形态学依据。本文还就WMD传入联系的比较解剖学和可能的生理学特性,以及TMB电镜组织化学方法作了初步的讨论。

Electron Microscopic Observation on White Matter Dendrites of Rat Spinal Motoneurons

White matter dendrites (WMD) of rat spinal motoneurons labelled retrogradely with choleragenoid horseradish peroxidase (CB-HRP) as well as those unlabelled were observed by electron microscopy. In ultrathin sections, a great number of axo dendritic synapses were found to exist along the courses of WMD. Synaptic vesicles were predominantly agranular spherical and ellipsoidal in shape. Agranular and granular vesicles were occasionally found to be co-existed in the same presynaptic button. The results have provided a morphological basis for the hypothesis of paral-ateral circuit regulating normal activities of spinal motoneurons. Anato-nical and physiological natures of afferent connections of the dendrites were discussed from phylogenetic point of view. Method for tetramethyl benzidine (TMB) reaction at electron microscopic level was also mentioned briefly.