Chronic phosphatidylserine treatment improves spatial memory and passive avoidance in aged rats.

Learning/memory deficits in senescent animals are widely used as a tool to evaluate the therapeutic potential of agents for treatment of age-associated cognitive dysfunction. As assessed in the Morris water maze test, aged (21-24 months) rats showed a variable loss of spatial memory. Aged non-impaired rats performed as well as young subjects, while aged impaired rats exhibited a severe and persistent place-navigation deficit. Passive avoidance retention was similarly affected in the two aged subpopulations. Chronic oral administration of phosphatidylserine (50 mg/kg/day for up to 12 weeks), a pharmacologically active phospholipid, was found to improve both the spatial memory and the passive avoidance retention of aged impaired rats. Results are discussed with reference to the phosphatidylserine-induced improvement of age-associated deterioration of brain functions in rats.