Enhanced learning of normal adult rodents by repeated oral administration of soybean transphosphatidylated phosphatidylserine

J Pharmacol Sci. 2005 Jul;98(3):307-14. doi: 10.1254/jphs.fp0050366. Epub 2005 Jul 9.


Soybean lecithin transphosphatidylated phosphatidylserine (SB-tPS) is already known to improve the learning ability of aged or drug-induced amnesic rodents. In this study, its effect on normal adult rodents was evaluated using several learning tasks. Firstly, three behavioral tests (open-field, Y-maze, and active avoidance test) were consecutively carried out after the daily oral administration of SB-tPS (50 mg/kg per day, for 34 days). Repeated oral administration of SB-tPS did not affect either exploratory behavior in the open-field test or spontaneous alternation behavior in the Y-maze test, while mice pretreated with SB-tPS showed significant enhancement of conditioned avoidance response. Secondly, the brightness discrimination test was used to evaluate the effect of SB-tPS on learning ability. The daily oral administration of SB-tPS (50 mg/kg per day, for 27 days) to normal rats significantly increased the correct response ratio in the brightness discrimination test. Finally, to elucidate the necessity of SB-tPS pretreatment, another active avoidance test was carried out, and no enhancement of conditioned avoidance response was observed in non-pretreated mice. These results suggest that repeated administration of SB-tPS could enhance the learning ability of normal adult rodents as those of aged ones.

MeSH terms

  • Acetylcholine / metabolism
  • Administration, Oral
  • Animals
  • Avoidance Learning / drug effects
  • Discrimination Learning / drug effects
  • Learning / drug effects*
  • Male
  • Maze Learning / drug effects
  • Mice
  • Phosphatidylserines / administration & dosage
  • Phosphatidylserines / pharmacology*
  • Rats
  • Rats, Inbred F344
  • Soybeans* / chemistry


  • Phosphatidylserines
  • Acetylcholine