SURVIVAL OF PARVALBUMIN-IMMUNOREACTIVE NEURONS IN THE GERBIL HIPPOCAMPUS FOLLOWING TRANSIENT FOREBRAIN ISCHEMIA DOES NOT DEPEND ON HSP-70 PROTEIN INDUCTION

HSP-70 was induced in the gerbil following 20 min of forebrain ischemi a. The induction, as revealed with immunohistochemistry, is stronger a nd longer-lasting in CA3 and dentate gyrus than in CA1. Most neurons i n this region, except GABAergic interneurons containing the calcium-bi nding protein parvalbumin, eventually cease to live as a result of del ayed cell death. Double-labeling of inducible HSP-70 and parvalbumin h as shown that no co-localization occurs in the hippocampus and neocort ex of the gerbil in this model of transient forebrain ischemia. These results show that different thresholds of sensitivity and vulnerabilit y exist for different subpopulations of neurons in the ischemic hippoc ampus, and suggest that HSP-70 protein induction is probably not essen tial for the survival of particular neuronal subpopulations subjected to transient ischemia.