Figure 1.

Cortical lesions incidental to preconditioning surgery or after freeze injury, and their effects on cerebral blood flow (CBF). Hematoxylin-eosin stained sections illustrate regions of cortical damage (*) 24 hours after middle cerebral artery (MCA) manipulation for ischemic preconditioning (IPC) or after intentional cryogenic lesions (CL). Larger lesions (>5 mm³) resulted in subcortical white-matter edema, sometimes propagating contralaterally (long arrows). CBF autoradiograms of the same sections illustrate local hyperemia, but more generalized CBF reduction after surgical injury or larger CL (compare signal intensities at the corresponding ipsilateral and contralateral locations, arrowheads).