Dual mode of synaptic transmission in the avian ciliary ganglion
Dual mode of synaptic transmission in the avian ciliary ganglion
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鸟类睫状神经节突触传递的双重模式
DOI：
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发表时间：
1963
期刊：
影响因子：
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通讯作者：
G. Pilar
中科院分区：
文献类型：
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作者：
A. R. Martin;G. Pilar
鸟的睫状神经节是特别感兴趣的，因为它的突触连接的不寻常的形态。在这些神经节中，有许多神经节细胞上的单个突触前纤维以杯状末端或杯状末端的形式终止。杯状体包围着轴突极附近的神经节细胞，发出大的指状突起，在细胞体上延伸相当长的长度。在其他细胞上，突触前纤维以弥散分支的终末网络结束。卡彭特（Carpenter）（1911）首次报道称，杯状结构是鸡、鸭和鸽子睫状神经节中最丰富的末端类型。Terzuolo（1951）描述了类似的结局，认为只存在于幼鸽中。后来，它们成为de Lorenzo（1960）用电子显微镜研究的对象。德·洛伦索对小鸡标本的电子显微照片表明，这些杯状结构可能足够大，可以被微量吸管穿透而不会造成过度损伤，从而可以从突触前神经末梢直接进行细胞内记录。神经节的生理学很少受到关注。Consiglio（1900）报告称，通过其的传播不被尼古丁阻断，这与哺乳动物睫状神经节不同（兰利&安德森，1892），Langendorff（1900）指出，动物因出血死亡后，通过鸟类神经节的传播异常持久。Carpenter（1911）认为，在这些不利环境中，神经节传递的持续性可能与杯状神经末梢的存在有关。在这里报告的实验中，从神经节细胞和突触前神经末梢获得记录。结果表明，在许多突触上，除了化学突触传递外，突触前和突触后元件之间还存在着直接的电耦合，而且这种耦合是双向的。关于这些发现的简要报告已经在其他地方发表（Martin &皮拉尔，1962 a，B）。
The ciliary ganglion of the bird is of particular interest because of the unusual morphology of its synaptic connexions. At many of these a single presynaptic fibre ends on the ganglion cell in the form of a cup-like termination, or calix. The calix embraces the ganglion cell near its axonal pole, sending out large finger-like processes extending for a considerable length over the cell body. On other cells, presynaptic fibres end in diffusely branching terminal networks. The calices were first reported by Carpenter (1911) as being the most abundant type of ending present in ciliary ganglia obtained from hens, ducks and pigeons. Similar endings were described by Terzuolo (1951) as being present only in young birds. Later they were the subject of investigation with the electron microscope by de Lorenzo (1960). De Lorenzo's electron micrographs of preparations from young chicks suggested that the calices might be large enough to permit penetration by a micropipette without undue injury, thus permitting direct intracellular recording from presynaptic nerve terminals. The physiology of the ganglion has received scant attention. Consiglio (1900) reported that transmission through it was not blocked by nicotine, in contrast to the mammalian ciliary ganglion (Langley & Anderson, 1892) and Langendorff (1900) noted that transmission through the avian ganglion was unusually persistent following death of the animal by bleeding. Carpenter (1911) suggested that persistence of ganglionic transmission in these adverse circumstances might be related to the presence of caliciform nerve terminals. In the experiments to be reported here records were obtained from both ganglion cells and presynaptic nerve terminals. The results indicated that at many of the synapses there was, in addition to chemical synaptic transmission, direct electrical coupling between presynaptic and post-synaptic elements and that this coupling was bi-directional. Brief reports of these findings have appeared elsewhere (Martin & Pilar, 1962a, b).