Nervous system of Schistosoma mansoni cercaria: organization and fine structure.
Nervous system of Schistosoma mansoni cercaria: organization and fine structure.
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曼氏血吸虫尾蚴的神经系统：组织和精细结构。
DOI：
10.1007/bf00935427
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发表时间：
1991
影响因子：
2
通讯作者：
Dorsey,CH
中科院分区：
文献类型：
--
作者：
Cousin,CE;Dorsey,CH
曼氏血吸虫尾蚴连续切片的透射电镜观察表明，神经系统分布于幼虫的三个解剖节，前部器官（口吸盘）、身体（中段）和尾部。中央神经节是一个由细胞体包围的神经堆，位于体节的前部。它向前逐渐变细成两个叶，一对前中枢神经干从叶中纵向延伸。中央神经节的后部区域逐渐变细成一对神经干（后中枢神经干）。12个周围神经干均匀分布在神经节周围。6条主干走行在前（前周围神经干）和6条走行在后（后周围神经干）。一对背侧和腹侧神经干，彼此相对，延伸到尾巴的长度。所有的神经干都没了鞘。神经系统包含三种类型的囊泡。I型囊泡平均直径为47.66±2.57 nm，电子密度不同，具有电子透明的外围。II型囊泡的平均直径为18.41±2.57 nm，电子透明，主要集中在突触和神经肌肉接头的突触前区域。III型囊泡的平均直径为57.47±16.08 nm。它们是电子致密的，主要集中在皮层纤毛乳头及其伴随的树突。存在两种类型的突触连接。1型突触的突触后膜中含有致密物质，而2型突触的突触前膜和突触后膜中含有各种尺寸的致密物质。突触和神经肌肉接头是相似的。
As observed by transmission electron microscopy of serially sectionedSchistosoma mansonicercaria, the nervous system is distributed throughout the three anatomic segments of the larva-i.e., the anterior organ (oral sucker), the body (midsegment), and the tail. The central ganglion, a neuropile surrounded by cell bodies, is located in the anterior area of the body segment. It tapers anteriorly into two lobes from which a pair of anterior central nerve trunks extend longitudinally. The posterior region of the central ganglion tapers into a pair of nerve trunks (posterior central nerve trunks). Twelve peripheral nerve trunks are evenly distributed around the ganglion. Six trunks course anteriad (anterior peripheral nerve trunks) and six course posteriad (posterior peripheral nerve trunks). A pair of dorsal and ventral nerve trunks, positioned opposite each other, extend the length of the tail. All nerve trunks are unsheathed. The nervous system contains three types of vesicles. Type I vesicles average 47.66±2.57 nm in diameter, vary in electron density, and have electron-lucent peripheries. Type II vesicles have a mean diameter of 18.41±2.57 nm, are electron-lucent and are concentrated mostly in the presynaptic area of the synaptic and neuromuscular junctions. The mean diameter of Type III vesicles is 57.47±16.08 nm. They are electron-dense and are concentrated mostly in the tegumental ciliated papillac and their accompanying dendrites. Two types of synaptic junctions are present. Type1synapse has dense material incorporated in its postsynaptic membrane, while Type2synapse has dense material of various dimensions incorporated in its presynaptic membrane and usually in its postsynaptic membrane. Synaptic and neuromuscular junctions are similar.