Figure 6. Responses of a viscerosensitive cell in the VPL nucleus to graded duodenal distention (0.2, 0.3, 0.4, and 0.5 ml). (A) Neuronal responses to graded duodenal distention before (CONTROL) and after a limited midline dorsal column lesion (DC1 LESION) and after a wider bilateral dorsal column lesion (DC LESION) at the C2 level. The histologic data for this animal are shown in Figure 1D and Figure 1E. (B) Spike shape throughout the procedures. (C) The dorsal column lesion area at the C2 level; the hatched area indicates the first midline lesion, and the dark area indicates the second wide bilateral lesion. (D) The dark area delineates the cutaneous receptive field on the shoulder. (E) The location of the neuron in the ventral posterolateral nucleus.