The effects of 2-ethyl-6-methyl-3-hydroxypyridine (3-HP) on age-related and alcohol-induced impairment of memory and learning were studied in rats and mice. 3-HP was found to accelerate the acquisition of the conditioned reflex of active avoidance and to improve the retention of the conditioned reflex of passive avoidance in old (24 months) rats. 3-HP consumption during chronic (5 months) alcoholisation improved learning ability and prevented lipofuscin accumulation in brain of ethanol-treated mice. Extrapyramidal disorders after systemic administration of MPTP and intranigral injection of MPP+ depended on age of animals, dose of MPTP and MPP+, and duration of administration. The beneficial effects of 3-HP on age-related impairment of memory and learning and experimental parkinsonian syndrome may be due to its ability to inhibit the peroxidation of membrane lipids and increase cell resistance to different disturbing actions.