Strain differences in quantitative analysis of the rat optic nerve

Abstract The cross-sectioned area of the optic nerve was largest in the gray, intermediate in the hooded, and smallest in the albino rat, and the mean fiber density was higher in the reverse order. The total fiber count, estimated from the two measures, was almost constant among the three strains, about 100,000 (94,700 to 110,300). Axon diameters of the optic nerve, ranging from 0.2 to 3.0 μm, were distributed in slightly larger values for the gray rat than for the albino rat.