The morphology of the Schwann cells and the unmyelinated fibers of a nerve supplying an immobilized muscle

Summary Hind limbs of cats were immobilized in the resting position for varying periods and the nerve supplying the medial head of the gastrocnemius muscle was studied while it was undergoing immobilization atrophy. Degenerative changes in the unmyelinated fibers and the Schwann, cells, followed by an abundant increase in collagen, were noticed after prolonged immobilization. Electron microscopic evidence that Schwann cells produce the collagen is discussed.