Motor mechanisms in the turtle spinal cord.

We reveal the intrinsic motor capacity of the spinal cord by examining motor behaviours produced by spinal segments caudal to a complete transection of the spinal cord. The turtle spinal cord generates three forms of the scratch reflex in the absence of neural inputs from supraspinal structures. Each form exhibits a characteristic motor neuron discharge pattern. We test the ability of the spinal cord to generate organized motor patterns in the absence of movement-related sensory feedback by examining motor neuron discharge patterns in spinal preparations that are immobilized with a neuromuscular blocking agent. The motor neuron discharge pattern associate with each form is observed in the spinal immobilized preparation. Each of these motor patterns is therefore generated centrally within the spinal cord.