CAJ | 학술논문

目的探讨放射线全脑照射对大鼠迟发性脑损伤后学习记忆能力和海马突触结构的影响.方法分组采用直线加速器对SD大鼠进行全脑照射,剂量分别为20 Gy和30 Gy.在照射前和照射后120d分别进行Morris水迷宫实验,分析各组大鼠行为学检测结果 ,采用平均逃避潜伏期和搜索策略两个指标评价大鼠学习记忆能力;同时用电镜和计算机图像分析仪观测模型鼠海马CA3区Gray Ⅰ型突触界面结构参数的变化.结果 20 Gy照射后120 d平均潜伏期为(41.17±10.76)s,搜索策略得分(27.13±2.34)分,30 Gy照射后120d平均潜伏期为(78.49±9.32)s,搜索策略得分(16.52±2.71)分,均与照射前及对照组差异有显著性.20 Gy照射后120 d海马突触后膜厚度为(22.03±6.84)nm,30 Gy照射后120 d海马突触后膜厚度为(23.19±7.65)nm,与放射前及对照组比均差异有差著性(P＜0.05).同时还观察到20Gy和30Gy照射后均较对照组突触活性带长度短,突触界面曲率小,突触间隙宽度变窄(P＜0.05).结论迟发性放射性脑损伤后学习记忆能力下降,并且可能与海马突触病理改变有关.
목적 탐토방사선전뇌조사대대서지발성뇌손상후학습기억능력화해마돌촉결구적영향.방법 분조채용직선가속기대SD대서진행전뇌조사,제량분별위20 Gy화30 Gy.재조사전화조사후120d분별진행Morris수미궁실험,분석각조대서행위학검측결과 ,채용평균도피잠복기화수색책략량개지표평개대서학습기억능력;동시용전경화계산궤도상분석의관측모형서해마CA3구Gray Ⅰ형돌촉계면결구삼수적변화.결과 20 Gy조사후120 d평균잠복기위(41.17±10.76)s,수색책략득분(27.13±2.34)분,30 Gy조사후120d평균잠복기위(78.49±9.32)s,수색책략득분(16.52±2.71)분,균여조사전급대조조차이유현저성.20 Gy조사후120 d해마돌촉후막후도위(22.03±6.84)nm,30 Gy조사후120 d해마돌촉후막후도위(23.19±7.65)nm,여방사전급대조조비균차이유차저성(P＜0.05).동시환관찰도20Gy화30Gy조사후균교대조조돌촉활성대장도단,돌촉계면곡솔소,돌촉간극관도변착(P＜0.05).결론 지발성방사성뇌손상후학습기억능력하강,병차가능여해마돌촉병리개변유관.
Objective To study the changes of learning-memory ability and synapse of hippocampus after radiation injuries. Methods Sprague-Dawley rats were grouped according to radiation dose to 20Gy group,30Gy group radiated by linear accelerator and control group were used before radiation and 120 days after radiation. Morris maze test were taken to study the learning and memory ability of rats in each group. Average escape latency and search strategy were scaled and analyzed in each group. The parameters of synapse in CA3 area of hippocampus were studied by using electron microscope and image analyzer. Results AEL of 20Gy group was (41. 17 ±10.76 ) s and score of SS was 27.13 ± 2.34 after 120 days' radiation but AEL of 30 Gy group was (78.49 ± 9.32)s and the score of SS was (23.19 ± 7.65 ) nm. There were significant statistic differences Compared with control group and before radiation (P ＜ 0.05 ). The thickness of PSD of 20 Gy group was ( 22.03 ± 6.84 ) nm after 120days' radiation and (23.19 ± 7.65 )nm in 30 Gy group. There were significant statistic differences compared with control group and before radiation. It was observed that both in 20 Gy and 30 Gy group' s the length of synaptic activity area was shorter,the curvature of synaptic interface was smaller,the width of synaptic cleft and the thickness of PSD was narrower than that of control group. Conclusion There was close relation between the changes of learning-memory ability and synapse of hippocampus after radiation injuries.