Figure 1.

Outcomes in the different settings with middle cerebral artery occlusion (MCAO). In the absence of ischemic preconditioning (IPC), MCAO induces a large infarction (ischemia-sensitive phenotype). IPC results early ischemic tolerance (IT) in minutes; if MCAO is applied during this phase, mainly cortical areas are spared (early ischemia-tolerant phenotype). In hours, the brain regresses to its naïve state. Delayed phase of IT occurs in days, when the latent cerebroprotective phenotype is complete, the brain is again ischemia-tolerant.