Toutant M, Bourgeois J P, Rouaud T, Toutant J P
Anat Embryol (Berl). 1981;162(3):325-42. doi: 10.1007/BF00299976.
Morphological and histochemical differentiation of neuromuscular spindles was studied in the posterior latissimus dorsi (PLD) of the chick during embryonic and post-hatching development. A rapid increase in the number of spindles takes place between the 13th and 15th of embryonic life. By the 15th day in ovo, the spindle capsule appears filled with numerous contiguous cells. Large sensory endings and small primitive motor endings are observed on intrafusal fibres. Ultrastructural observations of the nerve supply of the spindles confirm that each developing spindle receives one thick Ia axon with one to three thin gamma axons. The intracapsular space differentiates by the 17th day of embryonic development. All intrafusal fibres are morphologically of the nuclear-chain type, while two fibre types are distinguished as early as the 14th day of embryonic life, when myofibrillar ATPase activity is demonstrated after acid preincubation. These two histochemical types of intrafusal fibres are also described in the adult. The relation between these two histochemical types and different functional activity of intrafusal fibres is suggested.
在胚胎期和孵化后发育阶段，对鸡背阔肌后部（PLD）的神经肌肉梭进行了形态学和组织化学分化研究。在胚胎期第13至15天之间，梭的数量迅速增加。到胚胎期第15天，梭囊似乎充满了许多相邻的细胞。在梭内纤维上观察到大型感觉末梢和小型原始运动末梢。对梭神经供应的超微结构观察证实，每个发育中的梭接受一条粗的Ia轴突和一到三条细的γ轴突。在胚胎发育第17天时，囊内空间开始分化。所有梭内纤维在形态上均为核链型，而早在胚胎期第14天就可区分出两种纤维类型，此时在酸预孵育后可显示肌原纤维ATP酶活性。这两种组织化学类型的梭内纤维在成体中也有描述。文中还提出了这两种组织化学类型与梭内纤维不同功能活动之间的关系。
