Initiating or Blocking Locomotion in Spinal Cats by Applying Noradrenergic Drugs to Restricted Lumbar Spinal Segments

摘要: After an acute low thoracic spinal transection (T13), cats can be made to walk with the hindlimbs on a treadmill clonidine, alpha2-noradrenergic agonist. Because previous studies of neonatal rat cord in vitro suggest that most important lumbar segments for rhythmogenesis are L1-L2, we investigated role various initiation walking movements adult spinalized 5-6 d earlier. The locomotor activities were evaluated from electromyographic and video recordings. results show that: (1) localized topical application clonidine restricted baths over either L3-L4 or L5-L7 was sufficient induce movements. Yohimbine, antagonist, could block this locomotion when applied L5-L7; (2) microinjections one two L3 L5 also locomotion; (3) after intravenous injection blocked by yohimbine L3, L4, but not if L6; (4) all cases additional transections at L4. These it is possible initiate cat pharmacological stimulation number integrity necessary sustain activity.