Journal of Pharmacological Sciences (Jan 2005)

Enhanced Learning of Normal Adult Rodents by Repeated Oral Administration of Soybean Transphosphatidylated Phosphatidylserine

  • Akito Kataoka-Kato,
  • Makoto Ukai,
  • Masashi Sakai,
  • Satoshi Kudo,
  • Tsutomu Kameyama

Journal volume & issue
Vol. 98, no. 3
pp. 307 – 314

Abstract

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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. Keywords:: phosphatidylserine, learning, normal adult rodent, active avoidance, brightness discrimination