Spatial distribution of muscle fibers in a lumbrical muscle of the rat
Version of Record online: 26 JAN 2005
Copyright © 1993 Wiley-Liss, Inc.
The Anatomical Record
Volume 236, Issue 2, pages 381–389, June 1993
How to Cite
Gates, H.-J. and Betz, W. J. (1993), Spatial distribution of muscle fibers in a lumbrical muscle of the rat. Anat. Rec., 236: 381–389. doi: 10.1002/ar.1092360212
- Issue online: 26 JAN 2005
- Version of Record online: 26 JAN 2005
- Manuscript Accepted: 5 NOV 1992
- Manuscript Received: 2 MAY 1991
- Skeletal muscle;
- Motor unit;
- Muscle fiber type
The spatial distributions of two differnt populations of muscle fibers were measured in cross-sections taken from the mid-belly of adult 4DL muscles. Muscle fibers belonging to a single motor unit (identified by glycogen depletion) were distributed randomly in most muscles. Muscle fibers which contained slow myosin (identified immunohistochemically) were distributed nonrandomly, being evenly distributed throughout most of the muscle cross-section, but excluded from the edge of the muscle. Interpreted from a developmental perspective, the results are consistent with the proposals that slow myosin-containing fibers in the adult represent the original population of primary myotubes, and that the adult pattern of motor unit fiber type is achieved by synapse elimination from mismatched fibers rather than by conversion of fiber type. © 1993 Wiley-Liss, Inc.