Dorsal spinocerebellar tract: response pattern of nerve fibers to muscle stretch.
The response to muscle stretch of second-order neurons of the dorsal spinocerebellar tract was studied in anesthetized cats. Three different types of neurons are defined; the response of each type is remarkably similar to that of the corresponding stretch-receptors of the muscle. Accordingly, the cerebellum receives information on the mechanical situation in muscle from three qualitatively different channels: one has a high degree of sensitivity to dynamic stretch (Ia units) and provides a mixed signal of muscle length and speed of movement; another provides information mainly on muscle length (group-Il units); and the third signals information on the degree of contraction of the muscle (Ib units).
D000818:Animals; D002415:Cats; D002531:Cerebellum / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D012018:Reflex; D011984:Sensory Receptor Cells / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*