In addition, exercise increased the endocannabinoid anandamide levels and cannabinoid CB<sub>2</sub> receptors expression whereas it reduced Iba1 (microglial marker) protein expression as well as pro-inflammatory cytokines (TNF-α and IL-1β) in the spinal cord of mice with inflammatory muscle pain.
Differently, Iba-1 is downregulated after axotomy but upregulated after partial lesion of peripheral nerve as well as after virus inoculation and during non-inflammatory muscle pain.