Fig. 4.

A: perievent time rasters and histograms generated from cells recorded in the hindlimb somatosensory cortex while rats underwent treadmill-induced locomotion. Three cells simultaneously recorded from 1 normal (left) and 3 simultaneously recorded from 1 spinalized (right) rat are shown. Each cell had a significant response to the forepaw placements. Time zero on the x-axis indicates time of forepaw placement on the treadmill. The HL-SMC, unlike the forelimb, has significant overlap of sensory and motor function and, since the paw placements are sensorimotor events, it is not unusual for the responses to occur before paw placements (see Chapin and Woodward 1986 for a more complete description). B: response measures of cells in the hindlimb somatosensory cortex recorded around the time of forepaw placements during treadmill-induced locomotion. The background activity, response magnitude, peak response, and duration of response were significantly greater for cells recorded from spinalized rats compared with those from normal animal. No significant difference was observed in the peak latency for spinalized rats compared with normal.