【摘要】 本文用电镜对胎儿和新生儿基底杏仁核内突触和神经毡的发育进行了初步观察。结果表明,胎龄23周,神经毡主要有原始细胞突起组成,亦可见到轴突和树突,部分树突含有大量微管,微丝等;细胞突起间易见膜的特化,个别已具有典型突触结构,突触囊泡邻近突触活性点。胎龄37周,轴突和树突数量增加,其内微管数量减少,线粒体增多;可见轴树,轴体突触型式。生后4天,树突和轴突发育较好,个别树突可接受多个轴突终末的突触调节;除轴—树突触外,尚观察到轴—树突棘突触、轴—体突触和突触复合体;纤维髓鞘已经形成。出生后,仍可观察到正在发育的树突、突触等。本文对不同发育阶段突触和神经毡的机能意义进行了讨论。更多还原

【Abstract】 The synapse and neuropil of the basal amydaloid nucleus in 23-and 37-week-old human fetuses and newborns were studied by electron microscopy. When the fetal age was 23 weeks, the neuropil was charaeterised by the presence of numerous primitive cell processes and a few dendrites and axons. Some dendrites were packe with microtubules and neurofilaments. Paramembranous thickening between axon terminaI and dendrite were frequently seen in the neuropil. A few well established synapses were identified. Some vesicles clustered near the synaptic junction. At the 37th week, the number of dendrites and axons increased. Most synapses were asymmetric axodentritic type and some were symmetritic axodendrie synapses, occasionally axosomatic synapses were observed. 4days after birth,the axons and dendrites were well developed. Myelinatd fibers began to appear. Some dendrites were postsynaptic to several axon terminals. Although axodendritic synapse predominated, the axo-dendritic spine synapses, axosomatic synapses and synaptisc complexes were found. After birth, the growing dendrites and developing synaps could also be seen in the neuropil. The functional significance of synapse and neuropil in different developmental periods is discussed in the paper.更多还原