Skip to main content
. 2019 Jun 28;13:287. doi: 10.3389/fncel.2019.00287

FIGURE 9.

FIGURE 9

Effects of lentiviral-mediated MOR overexpression at the DRt on mechanical allodynia in SNI-animals. Representative photomicrographs of MOR-immunoreactive (IR) cells at the DRt of SNI animals injected with LV-EGFP (A) and LV-MOR-F (B). Typical MOR immunolabeling is marked by arrows. Scale bar in (B): 100 μm (A is at the same magnification). Data in (C) represent the number of MOR immunoreactive (IR) neurons after lentiviral vectors injection into the DRt at the injected (ipsilateral) and contralateral side. LV-EGFP (n = 6) or LV-MOR-F (n = 7) were injected at the DRt and their effects were assessed before (D0; i.e., 2 weeks after SNI induction) and 7 days (D7) after injection, by the von Frey test (D) which evaluates mechanical sensitivity. In an additional group of animals injected into the DRt with LV-EGFP (n = 6) or LV-MOR-F (n = 7), DAMGO at 10 ng was administrated at the DRt and its effects were assessed before (T0; i.e., 7 days after vectors injection) and 15 min (T15) after injection by the von Frey test (E). At D0 (i.e., 2 weeks after SNI induction; D) and D7/T0 (i.e., 3 weeks after SNI induction; D,E), all SNI animals presented a marked mechanical hypersensitivity, indicative of mechanical allodynia, as shown by the decreased withdrawal thresholds compared to the withdrawal thresholds of the age-matched naïve animals (n = 13) used in Figure 2 for the injection of saline or DAMGO. The withdrawal thresholds of naïve animals correspond to the values obtained before the injection of saline or DAMGO in those animals. Data in C,D,E are presented as mean ± SD. ∗∗∗p < 0.001 vs. T0; ###p < 0.001 vs. LV-EGFP.