CNR1 and amyotrophic lateral sclerosis: The cannabinoids mediated neuroprotective effects in ALS are proposed by three different mechanisms first, CB2R-mediated reduction in microglial activation and neuroinflammation with the possible association of PPAR-γ second, CB1R-mediated reduction in excitotoxic damage; and third, receptor-independent antioxidant effects of cannabinoids that might be related to PPAR-γ/Nrf-2 signaling [474].