AMINO-ACID RECOVERY VIA MICRODIALYSIS AND PHOTOINDUCED FOCAL CEREBRAL-ISCHEMIA IN BRAIN CORTEX OF RATS

A photochemical method using the Rose Bengal dye as thrombogenic agent was employed to induce focal cerebral ischemia in frontoparietal cort ex of rats. A transcerebral microdialysis probe was used to collect sa mples from ischemic cortical area. An increase in glutamate (6-fold) a nd in taurine (4-fold) within the first hour occurred. Neuropathologic al investigations demonstrate a reproducible damaged area surrounded b y a thin peripheral area showing neuronal apoptotic phenomena. The met hod represents a reproducible model of focal cerebral ischemia with ne uropathological aspects superimposable to those characteristic of thro mbogenic stroke in man. This method could also be relevant in the stud y of neurotransmitters during the evolution of ischemia. Furthermore, the presence of apoptotic phenomena in the perilesional halo confirms an ischemic penumbra suggesting the significance of preclinical pharma cological trials.