Fig. 8.

Hypothetical model for the role of rhythmic dCINs during locomotor-like activity. A, The phase relationship of dCINs can be related to not only the recorded cL2 activity (black trace) but also to the likely activity of the ipsilateral motor pool (iL2; top gray trace) and target MNs (cL5; bottom gray trace). The expected role of the L2–L5 dCINs is shown in thebottom trace and expanded in B.Exc, Phase of predominantly crossed iL2 to cL5 excitatory information; Inhib, phase of mainly inhibitory information. The gradient of the line, positive (+ve), negative (−ve), or 0, reflects the prevalent drive provided by CINs. Numbers at thebottom reflect the bins for the average firing frequency histograms such as those in Figure 3Bii–Dii.