King M G, Spencer A N
J Cell Sci. 1979 Apr;36:391-400. doi: 10.1242/jcs.36.1.391.
The morphological basis of impulse conduction in a jellyfish epithelium was investigated. Lanthanum impregnation of endodermal canal and endodermal lamella verified the existence of true gap junctions in Polyorchis. In both transverse and en face sections of gap junctions, electron-lucent globules, with a width of 7--8 nm and a spacing of about 11 nm, are evident. Gap-junctions are concentrated at the peripheral canal margin and septate junctions are localized around the canal lumen. Epithelial cells of the endodermal canals are capable of conducting a non-decrementing action potential. It is suggested that endodermal spike propagation, which can mediate 'crumpling' behaviour, is dependent upon low-resistence ionic pathways provided by gap-junctions and upon sealing of the intercellular space from saline extracellular fluids by septate junctions.
对水母上皮组织中冲动传导的形态学基础进行了研究。用镧浸染内胚层管和内胚层薄片，证实了多口螅中存在真正的间隙连接。在间隙连接的横向和正面切片中，宽度为7 - 8纳米、间距约为11纳米的电子透明小球清晰可见。间隙连接集中在周边管边缘，而分隔连接位于管腔周围。内胚层管的上皮细胞能够传导非递减动作电位。有人提出，可介导“皱缩”行为的内胚层尖峰传播，依赖于间隙连接提供的低电阻离子通道，以及分隔连接将细胞间隙与细胞外盐溶液密封起来。
