胎儿大脑皮层枕极突触超微结构的形态学观察与分析

本文用 H-600型透射电子显微镜观察了6例眙儿大脑皮层枕极245个突触的超微结构,结果表明在4.5个月胎儿枕极大脑皮层未见到突触,在5个月胎儿仅观察到少量突触,以后随胎龄的增加,突触数逐渐增多。在六个月以后胎儿大脑皮层,突触数明显增多,在新观察到的245个突触中,次轴树突触占绝大多数,占胎儿突触观察总数的77.6%。其次为轴棘突触,占胎儿突触观察总数的4.5%,从五个月胎脑开始观察到轴极突触,且这些轴棘突出的后成分中均不含有棘器。另外在胎儿枕极皮层,还观察到较多的轴-体突触,占胎儿突触观察总数的3.7%。此外,尚见到少量轴-轴,树-树,树-棘突触和串,并联突触。

Morphological observation and Analysis in Synaptic Ultrastructure in Fetal Occipital Pole of Cortex

The Types of synapses and some morphlological features of the synaptic submicroscopic structures of occipital pole of cortex in fetuses have been described in this study.A total of 245 synapses in fetuses was observed.No synapses were found in 4.5—month fetal cortex.There were a few synapses in 5—month fetus's.After then,the number of synapses increases gradually with the increasing fetal age and increases obviously from the 6th month.The percentage of axo-dendritic synapses in fetuses is 77.6%,it accounts for the majority of the synapses.The percentage of axo-spinous synapses is 4.5% in tetuses.There is no spine apparatus in the post synaptic element of fetal caxo-spinious synapses.More axo-somaticsynapses are observed in fetuses, the persentage is 3.7%.Besides simple synapse,rare patterns of synapses are observed,such as dendrodendritic,dendro-spinious synapses which is never reported in cerebrl cortex.The parallel synases and serialasynapases have also been found.