Motor innervation of the striated oesophagus muscle. Part 1. Intramural distribution of the right and left vagus nerve in the rat oesophagus as revealed by the glycogen depletion technique.

The muscularis propria of the rat oesophagus is entirely made up of striated muscle fibres. All fibres are of the same histochemical type, which is characterized by high activity of actomyosin ATPase, medium activity of oxidative enzymes and relatively strong reaction for phosphorylase. Prolonged stimulation (10 Hz, 30 min) of the vagus nerves causes depletion of the glycogen content of the oesophageal muscle fibres. This stimulation effect can be visualized by means of the PAS technique as well as by the histochemical reaction for phosphorylase. In 8 animals the right and in 8 animals the left vagus nerve were stimulated repetitively and the stimulated muscle fibres were identified in transverse sections of the oesophagi, stained for phosphorylase. The muscle fibres supplied by one vagus nerve are distributed all over the circumference of the oesophagus. In the upper third of the oesophagus stimulation of either vagus nerve depletes slightly less than 50% of the muscle fibres, whereas in the lower two-thirds the right vagus nerve seems to predominate to a certain degree. In 3 animals both vagus nerves were stimulated simultaneously. Bilateral stimulation produced a very extensive depletion. Only a few muscle fibres remained unaffected. Functional implications of the results, the question of polyneuronal innervation and the role of the myenteric plexus are discussed.