The Ranvier nodes in the neurogenic electric organ of the knifefish Sternarchus: a freeze-etching study on the distribution of membrane-associated particles.

摘要: The two types of Ranvier nodes (type I with narrow gap, type II giant gap) and internodes in nerve fibers composing theSternarchus electric organ have been studied by means freeze-etching electron microscopy. Numerical analysis the distribution membrane-associated particles revealed following features: (1) P-faces both internodal axon bear a similarly high density (1000–1200 particles/sq. μm on average). (2) particle is differential E-faces: histogram for has wider range concentrations (114–1522 μm) than that (45–576 whose values are same as those axon. At least some (narrow gaps) generate spikes probably low resistivity; these may be E-faces. E-faces associated resistivity absence excitability. Similarly, reflect inexcitability. There evidence transition from one nodal to next gradual: gap width increases, there an occurrence surface elaborations E-face tends drop towards nodes.