A histochemical study of the neuro-muscular spindles in the tongue of some rodents.

An investigation was undertaken to study the Neuro-muscular spindles in the tongue (Rattus rattus rufescens and Suncus murinus) by cholinesterase technique, under maintained pH of 5.2, incubation period 20 h., and temperature 38 degrees C (Rattus) and 39 degrees C (Suncus). Neuro-muscular spindles were observed frequently distributed from anterior to posterior of the tongue and took a little darker stain than the ordinary muscle fibres (negatively stained) while the nerve fibres and ganglia took still darker stain. Nerve fibres (myelinated, non-myelinated and tortuous) were seen penetrating and embracing the muscle spindles and most of them ran parallel to the spindles. Ganglia of various shapes (oval, irregular, elongated and rounded) and sizes (large, Rattus and medium and small, Suncus) were AChE-positive. Ganglia small and medium in size, rounded and elongated in shape were arranged in chain-like fashion on the muscle spindles in Suncus (Fig. 9, 10). The blood vessels (artery, vein, and capillary) were recorded either in close association with the muscle spindles or lying parallel to it. In all cases they were closely related and deeply associate either with the nerve fibres of the plexus of the muscle spindles or with the nerve fibres of the neural network of vessel. Perivascular and perimuscular ganglia with pre- and postganglionic nerve fibres were closely related to each other. Nerve endings, dot-like (Rattus) and bulb-like (Suncus) were occasionally recorded. AChE activity was found randomly in the muscle spindles (Fig. 2, 5.) and in the form of dark brown patches in the ordinary muscle fibres.