摘要
目的探讨大脑发育关键期后不同的营养方案对早产大鼠学习认知能力的影响。方法通过剖宫产法获得新生SD早产大鼠,仔鼠由代乳母鼠哺乳至21日龄。断奶后的早产仔鼠随机分为3组:早产标准蛋白组、早产低蛋白组和早产高蛋白组。从第22日龄起,低蛋白组给予低蛋白饲料(含8%蛋白质)喂养至实验结束,高蛋白组给予高蛋白饲料(含30%蛋白质)喂养至实验结束,标准蛋白组给予标准蛋白饲料(蛋白质含量18%)喂养至实验结束。各组大鼠分别在第6周和第8周进行Morris水迷宫实验,检测早产大鼠学习认知能力的改变。结果(1)定向航行实验:①早产大鼠6周龄时的逃避潜伏期在第3天和第4天的变化不明显,8周龄时的逃避潜伏期则随训练天数增加逐渐缩短。②8周龄早产高蛋白组大鼠的第4天逃避潜伏期明显低于6周龄早产高蛋白组大鼠(P<0.05)。(2)空间探索实验:①各组早产大鼠6周龄的穿越原平台时间和原平台所在象限时间占总时间的百分比差异均无显著性(P>0.05)。28周龄早产高蛋白组大鼠的穿越原平台时间和原平台所在象限时间占总时间的百分比均明显大于其余两组(P<0.05)。③8周龄早产高蛋白组大鼠的穿越原平台时间和原平台所在象限时间占总时间的百分比均明显大于6周龄早产高蛋白组大鼠(P<0.05)。结论在大脑发育关键期后的发育过程中,短时间加强营养的补给仍不能弥补早产对大鼠学习认知能力造成的损害。经过长时间高蛋白营养的补充,早产高蛋白组大鼠受损的学习认知能力可以得到恢复。早产大鼠的大脑发育过程中可能存在另一个发育关键期。
0bjectives To study the influence of different nutrition plans on learning and cognitive abilities of preterm rats after the critical period of brain development.Methods The neonatal SpragueDawley premature rats were obtained through the method of cesarean section.Premature new born rats were lactated to 21 days by nursing mother.Premature rats were randomly divided into three groups after weaning:preterm standard protein group,preterm low protein group,and preterm high protein group.After weaning,the low protein groups were fed low protein diets including 8%protein until the end of experiment.The high protein groups were provided with high protein diets including 30%protein until the end of experiment.The standard protein groups were fed standard protein diets containing 18%protein until the end of experiment.In each group,the rats were respectively tested at 6 weeks and 8 weeks.Morris water maze task was performed to assess the learning and cognitive abilities of the premature rats.Results(1) Directional navigation experiments:①At the age of 8 weeks,the escape latencies to rind the platform were shortened with increased training times for premature rats.The escape latencies of the premature rats did not change significantly in the third and fourth day of the experiment at the age of 6 weeks.②At the fourth day the escape latencies to find the platform of the 8-week-old premature rats of the high-protein group were significantly lower than the 6-week-old premature rats of the high-protein group.(2) Probe trial test:①At the age of 6 weeks,the time premature rats spent at platform was not significantly different.And the percent of time spent in target quadrant of premature rats was not significantly different.②At the age of 8 weeks,high-protein premature rats spent significantly longer time in target quadrant than the other two groups.And the percent of time spent in target quadrant of high-protein premature rats were significantly greater than the other two groups(P<0.05).③At the age of 8weeks,the time h
出处
《发育医学电子杂志》
2013年第1期1-6,共6页
Journal of Developmental Medicine (Electronic Version)
基金
广东省科技计划项目(粤科技规划字[2011]97号)
广州市科技计划项目应用基础研究专项重点项目(2011J4100046)
广州市医药卫生科技项目(201102A213149)
关键词
关键期
营养
学习认知能力
早产大鼠
水迷宫
Critical period
Nutrition
Learning and cognitive abilities
Premature rats
Water maze
