NO SYNTHASE AND FREE-RADICAL GENERATION IN BRAIN-REGIONS OF OLD RATS - CORRELATIONS WITH INDIVIDUAL BEHAVIOR

WE have investigated the activity of NO synthase (NOS) and generation of free radicals (FRG) in selected brain regions of old male Wistar ra ts. Using the emotional resonance test, two groups of rats were select ed for the experiment: passive, preferring dark space and active, pref erring light space. Highest NOS activity and FRG were seen in cerebell um. As a rule, NOS activity was lower and FRG higher in the respective brain regions of active rats than in passive rats. Positive linear in ter-regional crosscorrelations of NOS activity as well as of FRG were found. When all rats were assessed as one group, negative correlations between NOS and FRG in cerebral cortex were revealed.