Ngb expression in the ischemic penumbra. Panel A-C shows representative sections of Ngb expression (see arrows) and infarct distributions delineated by red lines in uninjured (sham), WT and Ngb-null pMCAo mice respectively. The bottom part of the panel shows high magnification images of the area in the white squares where black arrows point at Ngb expressing neurons and white at necrotic neurons. The areas above the red lines are tissue undergoing liquefactive necrosis identified by pyknosis, karyolysis, karyohexis and rapid tissue dissolution consistent with necrotic ischemic brain injury. Note how no increase in Ngb expression is seen within or adjacent to the penumbra area (Panel A-B bottom) in WT pMCAo compared to sham. Also please note how no Ngb staining is seen in the infarcted area (Panel B bottom) suggesting no selective sparing of Ngb expressing neurons. In D a western blot quantification of Ngb expression in sham (SE ± 0.15) and pMCAo WT (SE ± 0.092) mice relative to beta-actin is shown. A significant (p = 0.038) down regulation of Ngb was observed in the pMCAo group compared to the sham operated group. Lines indicate mean values. Scale bar 150 μm.