In vivo mapping of brain benzodiazepine receptor changes by positron emission tomography after focal ischemia in the anesthetized baboon.

The delayed and apparently transient increases in [11C]PK 11195 specific uptake in vivo presumably represent glial/macrophage reaction; the marked depression in [11C]flumazenil specific binding, which appears selective for synaptic damage, is both precocious and sustained and thus may be better suited for the early assessment of ischemic damage in humans.