Butler R
Am J Anat. 1979 Sep;156(1):115-20. doi: 10.1002/aja.1001560112.
The development of muscle spindles was studied using the tenuissimus muscle of the cat. Observations show that the intrafusal muscle fibers develop as two separate groups: one group represented by a single nuclear bag fiber while the second group comprises the second nuclear bag fiber in association with all the nuclear chain fibers. This grouping is most pronounced in the fetus and is clearly seen in neonatal kittens (i.e., up to 2 weeks of age). As the intrafusal fibers begin to separate from each other, the groupings become less noticeable, although this basic pattern is often retained in the adult. The pattern of intrafusal fiber grouping is most noticeable in the equatorial regions of the spindle and least noticeable in the polar regions. This is not the grouping of fibers which would have been expected from a consideration of existing reports on muscle spindles. The implications for spindle form and function are considered.
利用猫的薄肌研究了肌梭的发育。观察结果表明，梭内肌纤维分为两个独立的组：一组由单个核袋纤维代表，而第二组由第二个核袋纤维与所有核链纤维组成。这种分组在胎儿中最为明显，在新生小猫（即年龄在2周以内）中也清晰可见。随着梭内纤维开始彼此分离，这种分组变得不那么明显，尽管这种基本模式在成体中常常保留。梭内纤维分组模式在肌梭的赤道区域最为明显，在两极区域最不明显。这并非从现有关于肌梭的报道中所预期的纤维分组情况。文中还考虑了其对肌梭形态和功能的影响。
