Figure 1. Neural discharge from the cut ends of the left lumbar ventral roots and arterial pressure changes in a healthy rat.

Continuous increases in neural discharge recorded from the cut ends of the left lumbar ventral roots (L5 and L6) and arterial pressure changes during 30 s of electrical stimulation of the mesencephalic locomotor region (MLR) at 35 μA in a decerebrate healthy rat under neuromuscular blockade in which the locomotion threshold was 12 μA. In the other four rats tested, continuous increases in motoneurone discharge during MLR stimulation were also observed.