CAJ | 학술논문

目的探讨不同日龄的新生大鼠缺血缺氧脑损伤后早期认知功能的改变.方法选取SD新生大鼠46只,按照后期测试时间的不同,分为21日龄的大鼠23只(21日龄组),31日龄的大鼠23只(31日龄组),2组按照随机数字标法根据是否制备缺氧缺血模型分成21日龄造模组12只,21日龄假手术组11只,31日龄造模组12只,31日龄假手术组11只.采用改良Rice模型方法将21日龄造模组和31日龄造模组制成新生期大鼠早期认知功能障碍模型,假手术组均模拟皮肤切开分离颈总动脉,但不结扎,无缺氧.4组大鼠造模成功后采用Morris水迷宫测试空间定位学习能力及空间记忆水平.结束水迷宫测试后断头取脑,进行电镜及尼氏染色观察脑组织细胞形态及尼氏小体定量-神经细胞活力分析.结果经Morris 水迷宫实验发现,21日龄造模组和21日龄假手术组平均逃避潜伏期均明显落后于31日龄造模组和31日龄假手术组,差异有统计学意义(P＜0.05),另2个造模组平均逃避潜伏期亦明显落后于相应的假手术组,差异有统计学意义(P＜0.05).4组大鼠的平均穿台次数和平均台周Ⅰ区活动时间比较,差异均无统计学意义(P＞0.05),而21日龄造模组平均台周Ⅰ区活动路程明显低于21日龄假手术组,差异有统计学意义(P＜0.05),同时21日龄2组大鼠的平均台周Ⅰ区活动路程明显低于相应的31日龄2组大鼠,差异有统计学意义(P＜0.05).31日龄造模组平均台周Ⅰ区活动路程亦明显低于31日龄假手术组,差异有统计学意义(P＜0.05).电镜观察显示,2个假手术组缺血侧的海马组织神经细胞结构正常,突触前膜内少见线粒体,2个造模组神经细胞有不同程度核固缩表现及内质网扩张等,海马突触内见较多线粒体.经尼氏小体定量-神经细胞活力分析发现,2个造模组的右大脑皮质活力较相应的假手术组显著下降,差异有统计学意义(P＜0.01);31日龄组均较相应21日龄组升高(P＜0.01).结论早期缺血缺氧脑损伤大鼠存在认知功能障碍,31日龄大鼠的空间定位学习及空间记忆明显优于21日龄大鼠,可能与日龄的增加有关. 目的探討不同日齡的新生大鼠缺血缺氧腦損傷後早期認知功能的改變.方法選取SD新生大鼠46隻,按照後期測試時間的不同,分為21日齡的大鼠23隻(21日齡組),31日齡的大鼠23隻(31日齡組),2組按照隨機數字標法根據是否製備缺氧缺血模型分成21日齡造模組12隻,21日齡假手術組11隻,31日齡造模組12隻,31日齡假手術組11隻.採用改良Rice模型方法將21日齡造模組和31日齡造模組製成新生期大鼠早期認知功能障礙模型,假手術組均模擬皮膚切開分離頸總動脈,但不結扎,無缺氧.4組大鼠造模成功後採用Morris水迷宮測試空間定位學習能力及空間記憶水平.結束水迷宮測試後斷頭取腦,進行電鏡及尼氏染色觀察腦組織細胞形態及尼氏小體定量-神經細胞活力分析.結果經Morris 水迷宮實驗髮現,21日齡造模組和21日齡假手術組平均逃避潛伏期均明顯落後于31日齡造模組和31日齡假手術組,差異有統計學意義(P＜0.05),另2箇造模組平均逃避潛伏期亦明顯落後于相應的假手術組,差異有統計學意義(P＜0.05).4組大鼠的平均穿檯次數和平均檯週Ⅰ區活動時間比較,差異均無統計學意義(P＞0.05),而21日齡造模組平均檯週Ⅰ區活動路程明顯低于21日齡假手術組,差異有統計學意義(P＜0.05),同時21日齡2組大鼠的平均檯週Ⅰ區活動路程明顯低于相應的31日齡2組大鼠,差異有統計學意義(P＜0.05).31日齡造模組平均檯週Ⅰ區活動路程亦明顯低于31日齡假手術組,差異有統計學意義(P＜0.05).電鏡觀察顯示,2箇假手術組缺血側的海馬組織神經細胞結構正常,突觸前膜內少見線粒體,2箇造模組神經細胞有不同程度覈固縮錶現及內質網擴張等,海馬突觸內見較多線粒體.經尼氏小體定量-神經細胞活力分析髮現,2箇造模組的右大腦皮質活力較相應的假手術組顯著下降,差異有統計學意義(P＜0.01);31日齡組均較相應21日齡組升高(P＜0.01).結論早期缺血缺氧腦損傷大鼠存在認知功能障礙,31日齡大鼠的空間定位學習及空間記憶明顯優于21日齡大鼠,可能與日齡的增加有關.
목적 탐토불동일령적신생대서결혈결양뇌손상후조기인지공능적개변.방법 선취SD신생대서46지,안조후기측시시간적불동,분위21일령적대서23지(21일령조),31일령적대서23지(31일령조),2조안조수궤수자표법근거시부제비결양결혈모형분성21일령조모조12지,21일령가수술조11지,31일령조모조12지,31일령가수술조11지.채용개량Rice모형방법장21일령조모조화31일령조모조제성신생기대서조기인지공능장애모형,가수술조균모의피부절개분리경총동맥,단불결찰,무결양.4조대서조모성공후채용Morris수미궁측시공간정위학습능력급공간기억수평.결속수미궁측시후단두취뇌,진행전경급니씨염색관찰뇌조직세포형태급니씨소체정량-신경세포활력분석.결과 경Morris 수미궁실험발현,21일령조모조화21일령가수술조평균도피잠복기균명현락후우31일령조모조화31일령가수술조,차이유통계학의의(P＜0.05),령2개조모조평균도피잠복기역명현락후우상응적가수술조,차이유통계학의의(P＜0.05).4조대서적평균천태차수화평균태주Ⅰ구활동시간비교,차이균무통계학의의(P＞0.05),이21일령조모조평균태주Ⅰ구활동로정명현저우21일령가수술조,차이유통계학의의(P＜0.05),동시21일령2조대서적평균태주Ⅰ구활동로정명현저우상응적31일령2조대서,차이유통계학의의(P＜0.05).31일령조모조평균태주Ⅰ구활동로정역명현저우31일령가수술조,차이유통계학의의(P＜0.05).전경관찰현시,2개가수술조결혈측적해마조직신경세포결구정상,돌촉전막내소견선립체,2개조모조신경세포유불동정도핵고축표현급내질망확장등,해마돌촉내견교다선립체.경니씨소체정량-신경세포활력분석발현,2개조모조적우대뇌피질활력교상응적가수술조현저하강,차이유통계학의의(P＜0.01);31일령조균교상응21일령조승고(P＜0.01).결론 조기결혈결양뇌손상대서존재인지공능장애,31일령대서적공간정위학습급공간기억명현우우21일령대서,가능여일령적증가유관.
Objective To establish an early cognitive disorder model in rats and investigate the early cognitive functioning after ischemic hypoxic brain injury during the neonatal period. Methods Forty-six newborn Sprague-Dawley rats were randomized into a 21-d-old group and a 31-d-old group. These 2 groups were then subdivided into model and sham-operated subgroups (M21, n=12; SH21, n=11; M31, n=12; SH31, n=11). A model of neonatal early cognitive disorder was established in the rats of the M21 and M31 groups using a modification of Rice's method. Rats in the SH21 and SH31 groups received skin incisions and common carotid artery separation without ligation or hypoxia. Each group was tested with a Morris water maze. The rats were sacrificed after testing, and brain tissue was examined under the electron microscope. Nissl staining allowed Nissl body quantification and neurocyte acin the M21 group was significantly longer than in the SH21 group. The 31-d-old subgroups had shorter average escaping latencies than the corresponding 21-d-old subgroups. (b) Spatial memory: The average platform times, Ⅰ region times and Ⅰ region distances showed no significant differences among groups. ②Brain pathology (a) Gross appearance: Obvious ischemic hemisphere atrophy was observed in the M group, and no abnormality was observed in the SH group. (b) Electron microscopic observation: In the SH group cell ultrastructures in the ischemic hippocampus were normal. Karyopyknosis and dilated endoplasmic reticulums were found in the M group. More mitochondria were found in the presynaptic membranes of the ischemic hippocampus in the M group than that in the SH group. (c) Nissl body quantification and neurocyte activity analysis: Significantly less activity in the ischemic cortex was found in the M21 group compared to the SH21 group. More activity was observed in the 31-d-old subgroups than in the corresponding 21-d-old subgroups. Conclusions ①The neonatal rats with ischemic hypoxic brain injury had prolonged average escaping latency and depressed neuronal activity. ②The 31-d-old rats had better spatial localization learning ability than the 21-d-old rats.