Reproducibility in Nerve Morphometry: Comparison between Methods and among Observers

Table 1

Average morphometric parameters of the myelinated fibers from the proximal segments of the sural nerve of young (90-day-old) female Wistar rats, obtained by three different observers, using the semiautomated method.

	Observer 1	Observer 2	Observer 3
MF area (µm^2)	23.3±0.7	21.5±0.5	21.4±0.7
MF diameter (µm)	4.6±0.1	4.4±0.1	4.4±0.1
AX area (µm^2)	7.4±0.6	7.8±0.6	8.9±0.6
AX diameter (µm)	2.5±0.1	2.6±0.1	2.8±0.1
Myelin area (µm^2)	15.9±0.2^#†	13.7±0.4^∗†	12.5±0.4^∗#
G ratio	0.6±0.0	0.6±0.0	0.6±0.0^∗
MF counted	1058±42	975±53	1055±42
MF measured	873±35	838±42	838±41

MF: myelinated fiber; AX: myelinated axon. *indicates significant difference compared to observer 1; ^#indicates significant difference compared to observer 2; ^†indicates significant difference compared to observer 3 (one-way analysis of variance followed by the post hoc test of Holm-Sidak).