Figure 2.

Brain injury induces apoptotic cell death by distinct pathways. The intrinsic pathway is centered around signals emanating from the mitochondria, whereas the extrinsic or receptor-mediated pathway begins when death receptors bind to their ligands. The prototypical death receptor Fas is shown here. HSP70 and HSP27 have been shown to interfere with apoptosis as indicated in the figure. See text for more details. (FasL = Fas ligand; AIF = apoptosis inducing factor; Akt = protein kinase B; Apaf-1 = apoptosis protease activating factor-1; Cyt C = cytochrome c; JNK = c-Jun N-terminal kinase; Dyn = dynamin).