| Abstract: | Electrical activity in nerves to various hind-limb muscles was investigated in decerebrate and decapitated cats during fictitious scratching. By analogy with the phases of real scratchingaiming (flexion of the hip and ankle and extension of the knee) and scratching (the opposite movements in these same joints), the corresponding phases of motor discharges were distinguished. Depending on the type of these discharges the hind-limb muscles were divided into three groups. In the nerves to the muscles of group I activity was observed in the period of "initial aiming" and in the rhythmic "aiming phases" and was reciprocal to activity in the nerves to group II muscles starting the "scratching phases." Activity appeared in nerves to group III muscles both in the period of "initial aiming" and in the rhythmic "aiming phases" and "scratching phases." Passive forward deflection of the limb potentiated the "scratching phases" and weakened the period of "initial aiming" and the "aiming phases." The physiological significance of the organization of the central program and the design of the spinal scratching generator are discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 13, No. 1, pp. 48–56, January–February, 1981. |
