A NEW LEARNING-PARADIGM - ADAPTIVE-CHANGES IN INTERLIMB COORDINATION DURING PERTURBED LOCOMOTION IN DECEREBRATE CATS

Adaptive interlimb coordination was studied during perturbed locomotio n in experimental chronically decere brate cats. Perturbations were ap plied to the stance phases of the left forelimb using a newly develope d treadmill which consisted of three compartments, one each for the le ft forelimb, the left hindlimb and both right limbs. During the pertur bed locomotion, the treadmill belt for the left forelimb was driven at about twice the speed for the other limbs. During the first 1-50 pert urbed steps, the step cycles of both forelimbs showed marked fluctuati ons; thereafter, the animals achieved stable locomotion by slightly sh ortening step cycle durations, and also by adjusting durations of bisu pport phases asymmetrically in the left and right forelimbs. The prese nt method provides a new test paradigm for adaptive interlimb coordina tion in locomotion, which will be useful in studying neural mechanisms of motor learning involving cerebellar synaptic plasticity.