Fig. 1. Schematic of the pinch receptive field (RF) of a dorsal horn neuron. The location of the incision, mechanically sensitive area ( heavily shaded ), and mechanically insensitive area ( lightly shaded ) are depicted. The open circle depicts the site of placement of the blunt mechanical stimulus directly on the incision ( dark line ), and the filled circles represent the sites of application of von Frey filaments adjacent and distant to the incision.