The spleen contributes to stroke induced neurodegeneration through interferon gamma signaling

Delayed neuronal death associated with stroke has been increasingly linked to the immune response to the injury. Splenectomy prior to middle cerebral artery occlusion (MCAO) is neuroprotective and significantly reduces neuroinflammation. The present study investigated whether splenic signaling occurs through interferon gamma (IFN gamma). IFN gamma was elevated early in spleens but later in the brains of rats following MCAO. Splenectomy decreased the amount of IFN gamma in the infarct post-MCAO. Systemic administration of recombinant IFN gamma abolished the protective effects of splenectomy with a concurrent increase in INF gamma expression in the brain. These results suggest a role for spleen-derived IFN gamma in stroke pathology.