PMC

A–E. Comparison of cell numbers obtained by three different quantification techniques, the isotropic fractionator (IF), stereology of histological sections (Histo), and DNA extraction. All error bars=SEM. A. Comparison of IF, stereology and DNA-based quantification of cells in human and macaque monkey forebrain. emb, embalmic fixation; for, formalin fixation; ca, callosum; co, cortex. Note that IF and stereology yield about 80,000–90,000 cells/mg, while DNA extraction yields only a fraction (20,000 cells/mg). B. A paired Student’s t-test shows no statistically significant (n.s.) difference between the IF and stereology (p>0.4; the number on the bars indicates the number of independent experiments); data shown are for IF and stereology for formalin-fixed human forebrain samples and paraformaldehyde-fixed monkey forebrain samples. The number on each bar indicates the number of independent experiments. C. When stereology data (from panel B) are adjusted for maximal possible bias due to lost caps (+14%), the difference between the IF and stereology is still not significant (paired Student’s t-test). D. The glial density of human white matter differs from that of macaque white matter forebrain (Student’s t-test, using both IF and stereology data), but only when embalmic human samples are included; the difference in cerebellum was not significant; Cb, cerebellum; Fb, forebrain; hu, human; mo, monkey; n.s., not significant. E. The cerebellar white matter contains significantly lower glial cell densities than cortical white matter, in both human and macaque (based on both IF and stereology data).

A) Schematic of the techniques used to quantify the myelinated axons within sciatic nerve of rats. B) Total number of myelinated axons and % of nerve tissue within rat sciatic nerves. P values are shown, 6 animals per group. Only light microscopy stereology and histomorphometry were used. B) The size of axons, myelin, and myelinated fibers within rat sciatic nerves as measured by LM stereology, histomorphometry, and EM stereology. * represent p<0.05 compared to LM measurements. Error bar represent standard deviation. N=6 for all groups. Scale bar on light microscopy images represent 20 μm, scale bar on electron microscopy represent 2 μm.

Bland-Altman plots and histograms of the method score differences: (A) colocalization and stereology; (B) genie and stereology; (C) pathologist mean score and stereology. Horizontal line represents mean difference within limits of agreement, which are defined as the mean difference ± 2 standard deviations.

A) Myelinated fiber area measured per animal using LM, histomophometry and manual measurement. Represented as average with standard deviation. B) Average myelinated fiber area as measured by LM, histomophometry and manual measurement, error bar represent standard deviation, p value shown. C) Distribution of fiber size as measured by LM stereology and histomophometry. * represent p<0.05. No significant differences between the two distributions. N=6 for all groups