TNF and ischemia: Microglia activation has beneficial effects because it promotes the production of growth factors, such as brain-derived neurotrophic factors, and the removal of dead tissue and debris after ischemia; however, the release of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α), reactive oxygen species, and nitric oxide following the activation of microglia is detrimental [23,24,25].