Figure 10.

RSP-induced fictive locomotion depends on the synaptic integrity of the lumbar CPG. A, Schematic of experimental procedures. B, Integrated activities of lumbar ventral roots during an episode of fictive locomotion induced by the RSP. C, Wavelet coherence analysis of the recording in B showing a high coherence between bilateral L5 lumbar activities. D, Circular plots from the same recording indicating phase alternation between ipsilateral L2/L5 (top) and bilateral L5 (bottom) activities. E–G, Calcium-free aCSF applied selectively to the rostral lumbar segments (Th11–L3; E) of the same preparation abolishes RSP-induced rhythmic locomotor-like activity (F, G). H, Proportions of preparations (n = 6) in which L2 (top) and L5 (bottom) expressed tonic (unshaded; L5; 2 of 6), burst-like (dark gray; L5; 4 of 6), and no activity (light gray; L2; 6 of 6) during rostrolumbar application of calcium-free aCSF. J–L, Recovery of RSP-induced locomotor-like activity (K), with a strong coherence of left and right L5 bursts (L) and phase alternation after washout of the calcium-free solution (J).