Late prolonged discharges in the motor nerves of the hindlimbs and their relationship to locomotor rhythmicity in thalamically immobilized cats]

Effects of flexor reflex afferents stimulation were investigated on high decerebrated curarized cats. Stimulation of ipsilateral flexor reflex afferents evoked late long-lasting discharges in flexor nerves. Contralateral flexor reflex afferents stimulation evoked late discharges both in extensor and flexor nerves. Transition from late discharges to rhythmic discharges was observed. Early segmental reflexes were tonically depressed in thalamic in comparison with acute spinal cats. A similar tonic depression of segmental reflexes took place in acute spinal cats after DOPA injection. Segmental reflexes were distinctly modulated during late and rhythmic discharges. On the basis of the data available possible central mechanisms of the observed changes of segmental reflexes are discussed.