Studies on spinal ascending pathway for effect of acupuncture analgesia in rabbits

The effect of acupuncture needling in hindlimb points on the threshold of pain arising from the radiant heat applied to the snout of the rabbit has been evaluated both before and after various surgical lesions produced in the spinal cord. Section of the dorsal column alone at the level of T12-L1 could not produce any detectable change either of the pain threshold or of the effect of acupuncture on the pain threshold. Nor could the superficial lateral cordotomy seriously affect the analgesic effect of acupuncture. However, a lesion placed in the ventral two thirds of the lateral funiculus on the contralateral side could abolish almost completely this effect.