Figure 5.
The cannabinoid receptor CB1 has a role in the neuroprotective effect of THC. SR141716A, an antagonist/inverse agonist specific to the CB1 receptor subtype, was injected along with THC immediately before the intravitreal injection of NMDA. Effects of systemic SR141716A (1 or 2 mg/kg) and THC (2 mg/kg) on the NMDA (200 nmol/eye)-induced retinal neurotoxicity were determined by TUNEL analysis at 18 hours after NMDA injection. OCT-frozen eye sections (8 μm) perpendicular to the retinal surface were analyzed as described before. A: Representative retinal distribution of NMDA-induced TUNEL-positive cells in retinal sections after injection of THC along with SR-141716A. B: Dose-dependent attenuation by SR-141716A on the protective effect of THC on the TUNEL-positive retinal cells induced by NMDA. Values represent the mean ± SE of four experiments. *, Significant at P < 0.05. ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer.
