The effect of intrathecal administration of FA or vehicle (isotonic saline) on pinch-evoked responses of Vc neurons in the IANX or sham-control rats. A, B, Typical peristimulus time histograms (PSTHs) of Vc WDR neurons to pinch stimulus of the maxillary whisker pad skin following intrathecal vehicle (isotonic saline) or FA administration in sham-control (A) and IANX (B) rats; bin width, 500 ms. C–I, Response to brushing (C), 1.2 g pressure stimulation (D), 5.4 g pressure stimulation (E), 15.1 g pressure stimulation (F), 28.8 g pressure stimulation (G), 75.8 g pressure stimulation (H), and pinching (I) of the RF. J, Recording sites. Vehicle (saline), FA (30 min), FA (60 min), and W indicate intrathecal isotonic saline administration, 30 min after intrathecal FA administration, 60 min after intrathecal FA administration, and washout, respectively, in this and Figure 6 and Figure 7. Bars in A indicate the duration of pinching of the maxillary whisker pad skin. *p < 0.05, **p < 0.01 (IANX rats vs sham-control rats); #p < 0.05, ##p < 0.01 (vs vehicle-administrated rats). BG, Background.