Fig 2: PANX1 is required for the enhancement of firing activity in Vc neurons following SCC inoculation. (A) Representative image showing the brainstem. An illustration showing the transverse plane of the brainstem. The black circles indicate the area that responds to the tongue stimulation. (B) The RFs of the tongue 14 days after PBS injection with intracisternal (i.c.) administration of PBS (PBS + PBS), SCC inoculation with PBS (i.c.) (SCC + PBS), or SCC inoculation with 10Panx (i.c.) (SCC + 10Panx). The area surrounded by the red lines indicates the area that responds to the stimulus. Columns represent the average ratio of RF in the tongue. (C) Representative firing activities following stimulation with brush, non-noxious, noxious and pinch stimulation in PBS + PBS, SCC + PBS and SCC + 10Panx rats. (D–I) Columns represent the average number of spikes of background activity (D) and afterdischarge (E) and brush (F), non-noxious pressure (G), noxious pressure (H) and pinch (I) induced spikes in PBS + PBS, SCC + PBS and SCC + 10Panx rats. n = 5: PBS + PBS, n = 6: SCC + PBS, n = 4: SCC + 10Panx, * p < 0.05, one-way ANOVA followed by Tukey’s test. Data represent the mean ± SEM.

Fig 3: PANX1 contributes to the increment of phosphorylation of ERK in Vc neurons following SCC inoculation. (A–C) The representative images showing pERK Vc neurons in PBS + PBS, SCC + PBS and SCC + 10Panx rats on day 14 after inoculation. Scale bar = 200 µm. (D) Columns represent the average number of pERK-IR neurons in the Vc. Arrowheads indicate pERK-IR neurons. n = 5: PBS + PBS, n = 5: SCC + PBS, n = 5: SCC + 10Panx, * p < 0.05, one-way ANOVA followed by Tukey’s test. Data represent the mean ± SEM.

Fig 4: The possible involvement of PANX1 in the Vc in mechanical allodynia in the tongue following SCC inoculation. (A) Time course of mechanical head-withdrawal threshold with stimulation of the tongue in PBS-injected or SCC-inoculated rats. n = 8: PBS, n = 12: SCC, ** p < 0.01, *** p < 0.001, vs. Pre, one-way ANOVA post hoc Dunnet’s test; †† p < 0.01, ††† p < 0.001, vs. PBS, two-way repeated-measures ANOVA followed by Bonferroni’s test. Data represent the mean ± SEM. (B) Time course of mechanical head-withdrawal threshold with stimulation of the tongue in PBS-injected or SCC-inoculated rats with intracisternal administration of PBS or 10Panx. n = 9: PBS + PBS, n = 6: SCC + PBS, n = 10: SCC + 10 Panx, ** p < 0.01, *** p < 0.001, vs. SCC + PBS, two-way repeated-measures ANOVA followed by Bonferroni’s test. Data represent the mean ± SEM.