Experimental investigation of muscular neurotization in the rat

Reinnervation of a free muscle graft by nerves from an adjacent intact muscle is called muscular neurotization. This paper investigates the mechanisms and stimuli responsible for muscular neurotization in the rat. Sternohyoid or sternomastoid muscles were transplanted as free muscle grafts to the ventral surface of an intact sternohyoid muscle (feeder muscle). After several weeks the graft and underlying feeder muscle were removed together, frozen, serially sectioned, stained, and carefully examined for the presence or absence of nerves. It was concluded from a series of experiments that in this model muscular neurotization is a form of nerve regeneration. In order for muscular neurotization to occur, it is necessary to have (1) injury to the nerves of the intact feeder muscle and (2) a pathway upon which the regenerating nerves may grow into the graft.