Fig. 1.

Peripheral immune cells infiltrate the ipsilateral cortex after ischemic preconditioning. Ex vivo flow cytometry was performed on the (A, B) ipsilateral (IPSI) and (C, D) contralateral (CONTRA) hemicortices 72 h after a 15-min middle cerebral artery occlusion (ischemic preconditiong pulse). The number of cells is quantified in (E), and demonstrates an increase in the number of microglia (MG), as well as an influx of Ly6C^neg and Ly6C^pos macrophages (MP), as well as polymorphonuclear neutrophils (PMN) into the ipsilateral, but not the contralateral, hemicortex after a preconditioning stimulus [n = 17 mice (4 separate ex vivo flow cytometry preparations) *p < 0.01]. Experiments were performed as previously described [48]