人基底杏仁核突触和神经毡发育的初步观察

A PRELIMINARY OBSERVATION ON DEVELOPMENT OF SONAPSE AND NEUROPIL IN BASAL AMYGDALOID NUCLEUS OF HUMAN FETUS

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.