s there another critical period fbr brain growth in premature rats
SU Zhi-Wen, CUl Qi-liang, ZHANG Hui, et al
1．Deapmemnt of PediatrJcs，Ihe Third Affliated Hospital of Guangzhou Medical Universcily．Guangzhou 510510，China；2．Instimte 0f Neumscience GuangZhou Medical University Guangzhou，510510，China
Abstract: 【Abstract】objectiVes To study the innuence of difkrent nutrition plans on leaming and cognitive abilities of preterats after the cri“cal period of brain development．methods The neonatal Sprague—Dawley premature rats were obtained thmugh the method of cesarean section．Premature new born rats were lactated to 2 1 days by nursing mother．Premature rats were randomly divided into three groups after weaning：prefer standard pmtein gmup，preteHn low pmtejn gmup，and preternl high pro￡ein gmup．After weanin the low pmtein gmups were fed low pmtein diets including 8％pmtein until the end of experiment．The high protein groups were pmvided with high pmtein diets including 30％pIDtein until the end of experiment．The standedprotein groups were fed standard protein diets containing 1 8％protein until the end of experiment．In each group，the mts were respectively tested at 6 weeks and 8 weeks． MoⅡis water maze task was perfoⅡned to assess the leaHling and cognitive abilities of the premature rats．Results(1)Directional navigation experiments：q)At the age of 8 weeks，the escape latencies to find the platfb珊were shonened with increased training timesfor premature rats． The escape latencies of the premature rats did not change significantly in the third and fourth day of the experimem at the age of 6 weeks．②At the fourth day the escape latencies to find the pla of the 8一week—old premature rats of the high—protein gmup were significantly lower than the 6一week—old premature rats of the high—pmtein gmup．(2)Pmbe trialtest：①At the age of 6 weeks，the time premature rats spent at plaⅡbawas not significantly different．And the percent 0f time spent in taet quadrant of premature
rats was not significanⅡy different．②At the age of 8 weeks，high—protein premature rats spent significantly longer time in target quadmnt than the other two groups．And the percent of time spent in target quadrant of high—protein premature rats were signifcantly greater than the other two gmups(jkO．05)．③At the age of 8 weeks，the time high—protein premature rats spentat plaⅡband the percent of time spent in treat quadrant were significantly greater than the 6一week—old’s(P<0．05)．Conclusion In the development pmcess after the critical period of brain development，shon time strenhening nutrition supply still cannot make up for the damage of 1eaming and cognitiVe abilities in rats caused by the premature delivery．After a long—tenn high protein nutri“onal supplement，high—pmtein premature rats with impaired leding and cognitive ability could
get recoVery．The brain deVelopment pmcess of premature rat might haVe another development critical period．
苏志文 崔其亮 张慧 谭小华 范茜 陈盛强. 早产大鼠的脑发育是否存在另一个关键期[J]. 发育医学电子杂志, 2013, 1(1): 1-6.
SU Zhi-Wen, CUl Qi-liang, ZHANG Hui, et al. s there another critical period fbr brain growth in premature rats. Journal of Developmental Medicine(Electronic Version), 2013, 1(1): 1-6.
2013, Vol. 1 
