Figure 1.

Experimental design. A, The decerebrate rabbit was fixed in a rigid frame (points of fixation are indicated by “X”). The cooler was positioned on the dorsal surface of the spinal cord at T12. To assess the conductance in spinal pathways under the cooler, the stimulating (Stim) and the recording (Rec) electrodes were inserted into the ventral spinal pathways at T11 and L1, respectively. Activity of spinal neurons from L5 was recorded by means of the microelectrode (ME). To evoke PLRs, the hindlimbs were positioned on a platform (B) periodically tilted in the transverse plane (C). The tilt of the platform caused flexion of one limb and extension of the other limb. The contact forces under the left and right limbs were measured by the force sensors (B, Force L and Force R, respectively). D, Limb configuration at the two extreme platform positions obtained from video recording (H, K, and An: hip, knee, and ankle joints, respectively). E, Time trajectory of the platform angle (Tilt) and of the vertical position of the distal point of the right and left limb (Limb-R and Limb-L, respectively).