t. administration of AM1241. To examine microglia in the dorsal horn of the spinal cord, Cytoskeletal Signaling inhibitor expression of the microglial marker, Iba-1 was examined. Compared to non-neuropathic sham-operated rats given i.t. AM1241 or equivolume vehicle, CCI-induced neuropathy produced a robust bilateral increase in spinal cord dorsal horn Iba-1 IR (ANOVA, F(1,8) = 212.0; P < 0.0001 and ANOVA, F(1,8) = 62.28; P < 0.0001, respectively) (Fig. 5A and 5B). Surprisingly, AM1241 did not alter increased levels of spinal dorsal horn Iba-1 IR in behaviorally reversed rats (ipsilateral ANOVA, F(1,8) = 2.767; P = 0.1348, contralateral ANOVA,
F(1,8) = 0.1346; P = 0.7232) (Fig. 5A and 5B). Representative images taken from the spinal cord dorsal horn following i.t. vehicle injection Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical in sham- and CCI-treated rats are provided (Fig. 5C and 5D). Figure 5 Immunofluorescent intensity quantification of the spinal cord dorsal horn reveals differences in astrocyte activation but not microglial activation in neuropathic rats treated with AM1241. (A, B) Iba-1 expression increased within the ipsilateral and contralateral … GFAP to identify altered astrocyte responses In the superficial dorsal horn, where incoming signals from pain fibers are processed, histological observation reveals that astrocytes make intimate
contact with Inhibitors,research,lifescience,medical microglia that express CB2Rs (Romero–Sandoval et al. 2008a). Prior reports additionally show that following spinal CB2R activation in neuropathic rats, superficial dorsal horn GFAP IR is significantly reduced (Romero–Sandoval et al. 2009). Inhibitors,research,lifescience,medical Therefore, we examined GFAP IR in the dorsal horn following i.t. administration of AM1241. Compared to non-neuropathic control animals, neuropathic rats demonstrated a robust bilateral increase in dorsal horn GFAP IR (ipsilateral ANOVA, F(1,8) = 15.00; P = 0.0047; contralateral ANOVA, Inhibitors,research,lifescience,medical F(1,8) = 10.45; P = 0.0120) (Fig. 5E and 5F). In stark contrast, lower values of bilateral GFAP IR were observed from tissues of rats treated with i.t. AM1241 (ipsilateral ANOVA, F(1,8) = 41.38; P = 0.0002; contralateral ANOVA, F(1,8) = 17.63; P = 0.0030) (Fig. 5E and 5F). Corresponding
representative fluorescent images used for analysis are shown; sham-operated rats treated with either i.t. AM1241 or equivolume vehicle (Fig. 3G and 3H), or CCI-treated rats injected with either i.t. AM1241 or equivolume vehicle (Fig. 3I and 3J). Monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) MAGL Endocannabinoids known to produce anti-allodynic MycoClean Mycoplasma Removal Kit effects are metabolized via enzymatic hydrolysis by fatty acid amide hydrolase (FAAH) and/or MAGL (Basavarajappa 2007). Inhibition of FAAH or MAGL increases the bioavailablity of CNS endocannabinoids with a corresponding attenuation of neuropathic pain rats (Kinsey et al. 2009; Long et al. 2009). Whether FAAH and MAGL IR expression levels are altered in the dorsal horn following i.t. CB2R agonist injections in neuropathic rats, is unknown.