Figure 7.

Control of fictive locomotor steering by RSP. A, Schematic of experimental procedure. B, Integrated activities of lumbar ventral roots illustrating an episode of fictive locomotion induced pharmacologically (NMDA/5-HT) during which a symmetrical RSP is applied to the ventral surface of the caudal medulla. C, Scatter plot showing the evolution of the cycle period of lumbar motor bursts during the same recording. The dashed line indicates the period of the stimulus trains. D, Scatter plot showing the percentage range of RSP periods over which the locomotor cycle period could be entrained in a one-to-one manner (dashed line). E, Integrated activities of lumbar ventral roots illustrating an episode of fictive locomotion induced pharmacologically during which a left-biased RSP was applied. F, Scatter plot showing the evolution of lumbar ventral root burst durations during the same recording. The dashed lines indicate the durations of the left–right RSP trains. G, H, Same representations as in F illustrating the evolution of ventral root cycle periods (G) and phase relationships (H). T stim, period of the stimulation trains.