Intrafusal muscle fiber histochemistry following its motor reinnervation.

Extrafusab muscle fibers maintain uniform structural and histochemical characteristics over their entire length (4). This is unlike the behavior of intrafusal muscle fibers in mammalian muscle spindles that display regional structural and histochemical differences along the fiber length as shown by Banks et al. (1) and Kucera (8). In this study it has been noted that some intrafusal muscle fibers may become morphologically and histochemicalby abnormal in the course of muscle spindle motor reinnervation and the abnormalities may concern only focal fiber regions.