On the Inhibition of Transmission to the Dorsal Spinocere‐bellar Tract by Stretch of Various Ankle Muscles of the Cat

Abstract

Abstract Dorsal spinoccrebellar tract neurones activated from primary endings of muscle spindles (la DSCT units) are adequately excited from one muscle or a closely synergistic group of muscles. Inhibitory effects by stretch or contraction of other muscles have been examined in anesthetized cats. Consistent inhibitory effects were obtained from the gastrocnemius‐soleus (GS) muscle on la DSCT units of the flexor digitorum longus muscle (FDL) and the tibialis anterior‐extrnsor digitorum longus (TA‐EDL) muscles. The inhibition of TA‐EDL units was mainly inducrd by GS contraction. The FDL Ia units were inhibited by passive stretch of GS. It is suggested that GS tcridon organs were responsible for the inhibition of TA‐EDI. units and that GS primary endings were responsible for the inhibition of FDI, units. Thus, there appears to be a high degree of specificity also in the inhibitory actions on the DSCT neurones.