Antiallodynic Effects of Cannabinoid Receptor 2 (CB₂R) Agonists on Retrovirus Infection-Induced Neuropathic Pain

Figure 2

Lack of long-term antiallodynic effects of CB₂R agonists on hind-paw mechanical hypersensitivity. (a) LP-BM5-infected mice were randomly assigned into uninfected (UI) or infected (IF) groups (/group), and hind-paw mechanical hypersensitivity was assessed weekly via the MouseMet electronic von Frey system between 5 and 12 wk p.i. After LP-BM5 infection, synthetic CB₂R ligands were injected (5 mg/kg, i.p.) twice/wk starting at 5 or 6 wk (HU308) p.i. (red arrow). Assessment of hind-paw mechanical hypersensitivity was performed weekly 24 h after first injection of the indicated CB₂R ligand: (b) JWH015; (c) JWH133; (d) Gp1a; (e) HU308. Data are presented as the mean ± SE paw withdrawal threshold with /group. and vs. corresponding paw/wk p.i. (ANOVA with Fisher’s LSD post hoc analysis).

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