Ischemic damage and early inflammatory infiltration are different in the core and penumbra lesions of rat brain after transient focal cerebral ischemia

Abstract Clinical and experimental observations emphasize that inflammation is a direct risk factor for stroke. We performed a detailed histological and immunohistochemical analysis, assisted by digital morphometry, to compare the representative brain lesions in the ischemic core and penumbra in a rat model. Focal neuronal necrosis and degeneration were significantly more intense in the core, whereas inflammatory infiltration, MPO, CD68, CD3, FXIII, Cox-2, iNOS2, Arg-1 expressions were stronger in the penumbra. Our findings indicate that neuroinflammation affects the penumbra more than the core and suggest that targeted modulation of the cellular infiltrate could be exploited to save brain volume.