Antal M, Kraftsik R, Székely G, van der Loos H
J Neurocytol. 1986 Jun;15(3):303-10. doi: 10.1007/BF01611433.
With the aid of the cobalt labelling technique, frog spinal cord motor neuron dendrites of the subpial dendritic plexus have been identified in serial electron micrographs. Computer reconstructions of various lengths (2.5-9.8 micron) of dendritic segments showed the contours of these dendrites to be highly irregular, and to present many thorn-like projections 0.4-1.8 micron long. Number, size and distribution of synaptic contacts were also determined. Almost half of the synapses occurred at the origins of the thorns and these synapses had the largest contact areas. Only 8 out of 54 synapses analysed were found on thorns and these were the smallest. For the total length of reconstructed dendrites there was, on average, one synapse per 1.2 micron, while 4.4% of the total dendritic surface was covered with synaptic contacts. The functional significance of these distal dendrites and their capacity to influence the soma membrane potential is discussed.
借助钴标记技术，在连续电子显微镜照片中已识别出软膜下树突丛的青蛙脊髓运动神经元树突。对不同长度（2.5 - 9.8微米）的树突段进行计算机重建显示，这些树突的轮廓极不规则，并呈现出许多0.4 - 1.8微米长的刺状突起。还确定了突触接触的数量、大小和分布。几乎一半的突触出现在刺的起始处，这些突触具有最大的接触面积。在分析的54个突触中，只有8个在刺上，且这些是最小的。对于重建树突的总长度，平均每1.2微米有一个突触，而突触接触覆盖了树突总表面积的4.4%。讨论了这些远端树突的功能意义及其影响胞体膜电位的能力。
