Morphological changes and changes in cerebrovascular permeability, cerebral blood flow and local cerebral glycose utilization (LCGU) were correlated in gerbils subjected to 5 minute bilateral occlusion of the common carotid arteries. The observations revealed several significant events occurring after the ischemic insult: 1) The acute ischemic destruction of the neurons occurred in a strikingly selective manner in CA1 sector of the hippocampus, 3 days after release of arterial occlusion. 2) There were two openings of the bloodbrain barrier, presumably based on two different mechanisms. 3) Ten minutes after recirculation, there was a striking dissociation between cerebral blood flow and utilization of glucose which could be a major cause of injury to neurons occurring during the post-ischemic period.