Identification of muscle spindles by direct and indirect electrical stimulation of intrafusal muscle fibers.

In two series of acute experiments on 25 anesthetized cats methods of rapid identification of muscle spindles based on electrical stimulation either of fusimotor nerve fibers or directly of the intrafusal muscle fibers were tested. The methods used are more reliable tests for the identification of muscle spindles than the generally accepted method of investigating the velocity of conduction of excitation along a single afferent fiber, for receptors both of the joints and of the deep tissues may also be innervated by fibers of the same diameter.