Changes in mast-cell distribution in skeletal muscle after denervation.

Motor nerves are known to govern the structure of skeletal muscle. In the normal guinea pig diaphragmatic muscle, we found that mast cells were predominantly located in the central tendon. Following denervation, these cells became more numerous in the muscle itself than in the tendon. Therefore, nervous trophic influences are exerted on other tissue elements besides those which sustain transmission and contraction. Ascertaining mast-cell distribution in biopsies may help to elucidate denervation effects in motor neuron disease.