The effect of the repetitive propagation of action potentials on the structure of toad sciatic nerve myelin membranes: an x-ray diffraction study at 11 A resolution.

Equatorial sections of the x-ray diffraction patterns of myelin from toad sciatic nerves recorded at 11 A resolution during long supramaximal repetitive stimulation (240 Hz for two hours) were used to calculate the relative electron density profile of the myelin membranes in this physiological state. The profile was compared to the one determined for the same nerve at rest. The difference between the stimulated profile and the control profile was found to be statistically non-significant. Therefore, when the sciatic nerve fibers are excited the structure of the internodal myelin membranes does not significantly change at 11 A resolution.