Deterioration of spinal reflex in beagles orally ingesting clioquinol

Spinal reflex and neuromuscular functions were investigated in the beagles ingesting clioquinol over a long period. The twitch tension, the refractory period, the summation of contraction and the discharge of the muscle spindles of the gastrocnemius muscle were not significantly damaged in the treated beagles, whereas the response with long latency of the spinal reflex disappeared completely during the administration not in the control but in the treated dogs. The meanings of disappearance of the spinal reflex in the treated dogs are discussed in relation to the degenerative change in the fasciculus gracilis at the cervical level of the spinal cord.