Figure 1: The dichotomy of macrophages/microglia is displayed. Macrophages/microglia have been shown to recruit and reactivate T cells in the CNS and release many detrimental molecules such as proteases, inflammatory cytokines, and free radicals. Through the latter molecules and other mechanisms, macrophages/microglia have been reported to contribute to toxicity to neurons as well as oligodendrocyte precursor cells. Conversely, they have also been observed to aid in axonal regeneration and remyelination as well as assist in the clearance of inhibitory myelin debris. In addition, macrophages/microglia have been shown to release a variety of neurotrophic factors. It can therefore be seen that macrophages/microglia possess an array of detrimental and beneficial functions, with the balance being dictated by the temporal and spatial specifications following CNS injury.