Changes in the diameter of brain vessels and intensity of collateral blood flow typical of chronic ischemia were detected by magnetic resonance imaging in senescence-accelerated OXYS rats demonstrating reduced (compared to Wistar rats) research and exploratory activity. Histochrome (antioxidant drug) produced positive effects on cerebral vessels in OXYS rats by stimulating collateral blood flow and acting as a vasodilator agent. Analysis of correlations showed that these effects of histochrome were closely related to its capacity to activate research and exploratory activity and reduce anxiety of OXYS rats in the open field test.