斑马鱼端脑的微细形态与结构

Fine morphology and structure of telecephlon in zebrafish(Danio rerio)

为了深入了解斑马鱼端脑的微细形态和超微结构,采用光镜和电镜技术对斑马鱼端脑进行观察研究。斑马鱼端脑由左、右嗅球和左、右大脑半球构成。嗅球前方有一对嗅神经,后端伸出嗅茎与大脑半球联系。光镜下,嗅球组织结构从外向内依次为上皮层、神经纤维层、小细胞层和内部细胞层。大脑半球外部覆盖很薄的大脑皮,基部为纹状体,两者之间的腔隙为公共脑室。纹状体由神经核团和神经纤维构成。神经核团分布于纹状体周缘,主要有连前核、背嗅核、侧嗅核、视前核和脚内核等。神经纤维包括横行的前连合,纵行和斜行的中央嗅束和侧嗅束。电镜下,嗅球分层明显,可观察到僧帽细胞、神经胶质细胞和众多突触。大脑半球中可见神经胶质细胞、突触以及血脑屏障系统等。斑马鱼端脑形态结构与大多数硬骨鱼相似,但有个别核团存在差异。实验结果可为斑马鱼神经生物学模型的建立与应用提供有效的理论基础。

In order to study the fine morphologyand ultrastructure of telencephalon in zebrafish( Danio rerio) deeply,light microscope and electron microscope were adopted to observe the telencephalon of zebrafish brain. The telencephalon consists of olfactory bulbs and the cerebral hemispheres. A pair of olfactory nerves lie anterior to olfactory bulbs,and olfactory bulb connects with the cerebral hemisphere through olfactory stalk. The olfactory bulbs were composed of epithelium layer,nerve fiber layer,glomerular layer and internal cellular layer from external to internal under light microscope. Cerebral cortex covers on the cerebral hemispheres and striatum is located in the base of cerebral hemispheres. And public ventricle emerges between the cerebral cortex and the striatum. The striatum comprised nerve nuclei and nerve fibers.Nerve nuclei including dorsal olfactory nucleus,lateral olfactory nucleus,preoptic nucleus and entopeduncular nucleus,which are located in the periphery of the striatum. Nerve fibers include commissure anterior,longitudinal central olfactory tract and lateral olfactory tract. M itral cells and synapses can be observed in the nerve fiber layer and glomerular layer of olfactory bulb under electron microscope. Besides,the astrocytes,synapses and blood-brain barrier system also arise in the cerebral hemispheres through TEM. The morphological structure of telencephalon in zebrafish is similar to those in other teleosts,but still exist individual differences in some nuclei. Thus,the results of this study can provide a theoretical reference for the establishment and application of zebrafish's neurobiological model.