Figure 3
(A) A micrograph of nerve cross-section with an unbiased counting frame superimposed on it. Axons within the unbiased counting frame that are in countable position were marked with stars. Toluidine blue staining, scale bar = 10 μm. (B) The same micrograph with the point counting grid superimposed on it. If an axon is crossed with the right corner of the unbiased counting frame during systematic random sampling, cross section areas of this axon was estimated by means of counting the test points of grid coincide into the axon.