Figure 3
From: Pain sensitivity increases with sleep disturbance under predictable chronic mild stress in mice
Quantitative sensory testing for pain. The water (W) group had lower mechanical pain threshold on days 2 and 21 of the predictable chronic mild stress (PCMS) based on the results of the tail clip test (a). The mesh wire (MW) and W groups were more sensitive to thermal pain on both day 2 and day 21 of the PCMS according to the faster latency in the tail immersion test (b). The hot plate test frequency on day 2 and day 21 revealed greater pain for the MW and W groups (c). There was noticeable increase in orofacial pain sensations brought about by decrease in the number of licks in the W group at 33 °C on day 2 and in the MW and W groups at 7 °C on day 21. The orofacial pain sensitivity was assessed using the orofacial pain assessment device (OPAD) (d). N = 6–8 per group (tail clip, tail immersion, and hot plate); N = 8–10 per group (OPAD); *p < 0.05, **p < 0.01, ***p < 0.001; one-way ANOVA followed by Dunnett’s or Tukey’s multiple comparison test. Data are presented as means ± SEM.
