The role of the VPL in the neural activation of LHb following ulnar MS. (A) Extracellular single-unit recordings in the LHb during ulnar MS. Representative waveforms (A1) and peri-stimulus time histograms (A2). Single-unit activities of LHb neurons were markedly evoked during ulnar MS (n = 7) (A2–3). # p < 0.05 vs. Before. (B) Ulnar stimulation (MS, n = 5; B2, B4) significantly increased the numbers of c-fos immunopositive cells, compared to control (Con, n = 5; B1, B4), which was prevented in the rats injected with ibotenic acid into VPL (VPL X, n = 5; B3–4). # p < 0.05, Con vs. MS; *p < 0.05, MS vs. VPL X + MS. Bar = 20 µm.