Memory retention in old rats: improvement by orotic acid.

The effect of methylglucamine orotate (MGO) on learning and memory was investigated in 24-month-old rats using brightness discrimination in a Y-chamber and active avoidance in a shuttle box. In both learning procedures, an improvement of memory retention following 5-day MGO treatment (225 mg/kg per day) was observed. The retention of untreated old animals was significantly lower compared to 8-week-old rats. MGO treatment resulted in a significant improvement of retention in old rats, which nearly compensated for their memory deficit.