[Morphological changes in the electrically inactive afferent myelinated nerve fibers of the live clustered...

At attempt has been made to determine morphological criterium of active and inactive alive afferent myelin fibers. Applying electrophysiological control, external diameters in the area of maximal dilatation of the myelin fiber are compared with the neighbouring maximal narrowing of the unmyelinated preterminal. The dilatation coefficient, suggested by the authors of mathematical models of the nervous fiber is taken as the base of estimation. When the dilatation coefficient is more than five, the fiber is considered to be inactive. The active and inactive nervous fibers are stated to possess certain morphological differences. They are observed not only in the first myelin segment area, but in the second one, and sometimes--in the third and fourth segments. Morphological characteristics of these segments make it possible to suggest that electrical impulse can be blocked. From our data it is possible to think that not only the first myelin segment and the first node of Ranvier, but also the successive segment and nodes of Ranvier influence the impulse passing.