TNF and infection: However, microglia become readily activated in response to injury, infection, or inflammation and are capable of producing a variety of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2) and reactive oxygen species, pro-inflammatory cytokines, including interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α), and potentially neurotoxic compounds [2,3].