Effect of DHA supplementation during development on rats spatial learning and memory ability

To investigate the effects of dietary supplementation of DHA oil during development of rats on the spatial learning and memory ability,a total of 144 neonatal male SD rats(1 month old) were randomly divided into 6 groups according to the method of random digits table: negative control group fed normal feed,negative control group fed essential fatty acid-deficient feed,positive control group(Piracetam 400 mg/(kg·d)),low,middle and high dose of DHA group(150,300,600 mg/(kg·d)),twenty-four rats in each group.After 4 weeks,8 weeks and 12 weeks of administration respectively,the spatial learning and memory ability were detected by Morris water maze test,and after that the level of total protein,acetylcholinesterase(AChE),superoxide dismutase(SOD),malondialdehyde(MDA) in the brain tissue of rats and blood routine were determined.In the Morris water maze test,at 8 weeks of administration,compared with negative control group,the escape latency decreased significantly(P0.05) in positive control group and middle dose of DHA group,the ratio of the effective time and the number of crossing-platform increased significantly(P0.05).At 12 weeks of administration,compared with negative control group,the escape latency increased significantly(P0.01) in high dose of DHA group,MDA content of brain increased significantly(P0.05),the activity of SOD decreased significantly(P0.05),and there was no statistical significance among the other groups about the indexes of AChE,SOD,MDA.The research showed that supplementation of DHA during development of rats improving the spatial learning and memory ability had significant dose-effect and time-effect relationship.Supplementation of large dose of DHA for long time during development of rats could reduce the spatial learning and memory ability.