FIGURE 1.

The forepaw barrel subfield (FBS) serves as our template to summarize results of lower jaw-to-forepaw remapping following forelimb deafferentation. The rat forepaw consists of glabrous ventral and hairy dorsal skin surfaces and a line drawing illustrating these surface features, along with nomenclature designating individual digit and pad regions, is illustrated in Figure 1(a). The ventral glabrous surface contains digit two (D2v) through D5v, a small D1v, three underlying digit pads (P1–P3), and well-demarcated thenar (TH) and hypothenar (HT) pads. The dorsal surface is covered by hairy skin overlying D1d through D5d, a dorsal hairy hand region (Hd), and a dorsal wrist region (Wd). The forepaw skin surface is represented in the FBS, and this subfield is reconstructed in the line-drawing in Figure 1(b). Four mediolaterally running rows of barrel-bands (dashed lines) can be seen that represent glabrous digits D2d–D5d); each barrel band is further divided into distal (d’), middle (m), and proximal regions. The representations of digit pads, pad one (P1) through P3, located beneath the four-barrel bands, and thenar (TH) and hypothenar pads are also shown. The dorsal surface of D1 (D1d) and the ventral surface of D1 (D1v) are represented by single barrels in the rostral-most part of the FBS. The dorsal hairy digit skin is represented by a lateral strip overlying the glabrous barrels and designated as D2d through D5d, overlying their respective barrel bands. Adapted from Waters et al. 1995.