Figure 6.

Influence of stimulation of middle and hindleg load sensors on coxal motoneuron activity as a function of walking direction. A, Recording of RetCx and ProCx activity from the appropriate leg nerves of the mesothoracic segment with ongoing stimulation of load sensors. Note the reversed effect during forward (i) and backward (ii) walking. B, Bar diagrams showing the occurrence frequency of transitions in motoneuron activity of the thoraco-coxal motoneurons in middle legs (white bars) and hindlegs (black bars) during stimulation of load sensors during forward and backward walking. i, Increase in load; ii, decrease in load. Numbers above the columns indicate the number (n) of stimuli evaluated for the hindleg (filled bars) and the middle leg (open bars), respectively. The sketches beneath the diagrams outline the two different cases, i.e., ProCx or RetCx motoneurons being currently active (bars) during caudal (upward deflection of the CS stim. trace) or rostral (downward deflection of the CS stim. trace) bending and the subsequent transition in activity.