Figure 3.

Double-referent phase measurement of the RC rhythmic firing. A, Schematic of technique used to measure double-referent phase of RC activity (top trace) during locomotor-like activity with respect to the i-L2 activity (L2VR; bottom trace). The latencies for RC spikes (arrowheads) were measured with respect to the normalized ON and OFF phases of i-L2. For additional details, see Materials and Methods. B, Bar diagrams of the duration of the mean ± SD firing of all recorded RCs. RCs that fired preferably in the flexor (ON) phase are indicated by open bars (n = 11), whereas those fired in the extensor (OFF) are indicated by filled bars (n = 11).