Muscle fiber cross sectional area.

Mean fiber cross sectional area (CSA) measurements were obtained from a minimum of 500 fibers in each muscle for plantaris muscle fibers that expressed type I, IIA, or IIB myosin heavy chains in hindlimb suspension (A) and recovery (B) groups. Four images from non-overlapping regions of each tissue cross-section stained for individual MyHC fibers were used for muscle fiber CSA measures. All images were taken with a Zeiss LSM 510 Meta confocal microscope at a magnification of 20X. Mean fiber CSA of respective fiber types was determined by planimetry. * P<0.05 vs. cage control.