S100B and brain infarction: According to the results of H&E: tMCAO induced brain infarction: the peripheral neuron was nuclear pyknosis accompanied by the deeper staining: the penumbra area was swollen: neuropil vacuolation: glial cell hyperplasia: and Nef administration alleviated all the adverse phenomena elicited by tMCAO (Fig. 3a): dose-dependently.