Intakes of dietary docosahexaenoic acid ethyl ester and egg phosphatidylcholine improve maze-learning ability in young and old mice.
The effect of dietary docosahexaenoic acid (DHA) [22:6 (n-3)] ethyl ester (EE) and egg-phosphatidylcholine (PC) on maze-learning ability in young and old mice was studied. Male Crj:CD-1 mice aged either 3 wk or 14 mo were fed a diet containing 2 g DHA-EE/100 g diet plus 3 g palm oil/100 g diet (DHA-EE Group), 5 g egg-PC/100 g diet (egg-PC Group), 1 g DHA-EE/100 g diet plus 2.5 g egg-PC/100 g diet plus 1.5 g palm oil/100 g diet (DHA-EE + egg-PC Group) or 5 g palm oil/100 g diet (Control Group) for 5 mo. Maze-learning ability was assessed 4 mo after the start of the experiment. The time required to reach the maze exit and the number of times that a mouse strayed into blind alleys in the maze were measured in three trials every 4 d. In trial 2 of young mice, performed on d 4 after the first trial, the DHA-EE group required less (P < 0.05) time to reach the maze exit and DHA-EE and egg-PC groups strayed (P < 0.05) into blind alleys fewer times than the control group. In trial 2 of old mice, the DHA-EE, egg-PC and DHA-EE + egg-PC groups needed less (P < 0.05) time to find the exit and spent a fewer (P < 0.05) number of times in blind alleys than did the control group. The DHA-EE, DHA-EE + egg-PC and egg-PC groups strayed into blind alleys fewer times than the control group in trial 3 of old mice (P < 0.05). Our results suggest that the intake of DHA-EE and the egg-PC diet effectively enhances maze-learning ability and brain functions in old mice.
Lim
S Y
SY
National Food Research Institute, Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Suzuki
H
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D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D004032:Diet; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D051379:Mice; D010713:Phosphatidylcholines / Q000008:administration & dosage / Q000494:pharmacology*
D010713:Phosphatidylcholines; D004281:Docosahexaenoic Acids; C067518:4,7,10,13,16,19-docosahexaenoic acid ethyl ester