Three-dimensional graphs showing the topographic stereotaxic distribution of selectively nociceptive units and clusters recorded in VMpo . (A) shows case m154 and (B) shows case m57, the two cases for which histological evidence is shown in Figure 3 (C) shows a collation of five cases (m57, m65, m86, m154, and m177), in which the geometric means were aligned for the recordings with RFs on the hand in each case. Units and clusters with RFs in region 1 (face, head, ear and neck) are indicated by filled circles, in region 2 (hand, arm, shoulder, and chest) by open squares, and in region 3 (foot, leg, abdomen, rump, and tail) by crossed diamonds. The vertical dimension indicates recording depth, the left top angled dimension the Medio-Lateral stereotaxic coordinate, and the right top angled dimension the Antero-Posterior coordinate, all in units of millimeters.