The molecular events in acute stroke can be divided in several stages. First, within minutes the hypoxia and energy deficiency lead to immediate cell death. In a second step, there is a rapidly developing inflammatory reaction involving local and peripheral immune cells. This inflammatory reaction influences not only the initial infarct growth but also the long-term recovery. Using state-of-the-art techniques, we aim to decipher immunological mechanisms that influence the neurological outcome after a stroke in the short and long term. A particular focus of our work is on the highly conserved pro inflammatory cytokine Interleukin-17A, IL-17A-producing innate lymphocytes and meningeal immune cells. We try to understand on the one hand how IL-17A influences the early inflammatory response and on the other hand what effects the cytokine has on long-term regeneration. The investigation of long-term effects is of high relevance since it is now established that IL-17A not only triggers immunological cascades but also has direct effects on neurons and can thereby influence behavioral memory and learning.