摘要
目的探讨关键期内剥夺性弱视治疗前后视皮层神经元功能状态的改变,论证NO在视觉发育可塑性及剥夺性弱视发病机制中的作用。方法2周龄健康雄性SD大鼠接受左眼睑缝合术造成剥夺性弱视模型,术后2周打开左眼并行对侧眼眼睑缝合遮盖治疗。应用SABC免疫组织化学法检测各组大鼠脑组织视皮层17区切片nNOS阳性神经元在反缝治疗前后的表达;应用Td2000真彩色细胞图像分析系统进行视皮层17区nNOS阳性神经元胞体截面积和树突总长度测量。结果反缝治疗前(术后2周)单纯剥夺组较同龄正常对照组视皮层17区nNOS免疫阳性细胞密度(Ⅳ层除外)明显降低(P<0.05);胞体截面积和树突总长度明显减少(P<0.01)。治疗后(术后4周)除剥夺组视皮层17区胞体截面积较同龄正常对照组减少外(P<0.05),其余各层nNOS阳性神经元密度、胞体截面积和树突总长度比较差异均无统计学意义(P>0.05)。结论nNOS在大鼠视觉中枢的表达具有时空特异性,说明NO在敏感期的早期及中期参与视皮层的可塑性变化,在敏感期后期,NO可能通过其他机制影响视皮层的可塑性发育。
Objective It was confirmed that nitric oxide（NO） participates in the plasticity development of retina,lateral genieulate body and anterior eolliculi. But the effects of NO on visual cortex development is below clear. This study aimed to observe the expression of nerve nitric oxide synthetase（nNOS） in visual cortex 17 area of rats with monocular deprivation. Methods The eyelids of lateral eyes of 14-day-old male Sprague Dawley （SD） rats were sutured for 14 days to create the myopia models. The rats were randomly divided into monocular deprivation group（ 12 rats） with sutured left eyelids at postnatal day 14 and biocular alternative suture group （6 rats, at 14-day interval）. Twelve normal rats were used as controls. The expression of nNOS in visual cortex 17 area was examined by SABC immunohistochemistry and measuring area and total length of dendrite of positive neuron by Td2000 image analysis system. Results Visual cortex 17 area were divided into 6 layers by Nissl dyeing： molecular layer （ Ⅰ layer） , external granular layer （ Ⅱ layer） , external pyramidal layer （ Ⅲ layer） , internal granular layer （ Ⅳ layer） ,internal pyramidal layer（ Ⅴ layer） ,polymorphous cell layer（ Ⅵ layer）. The positive cell densities for nNOS in Ⅱ/Ⅲ ,Ⅴ layers, Ⅵ layer of visual cortex 17 area were significantly reduced in 6-week rats of normal group compared with 4-week rats of normal group（tⅡ/Ⅲ=3.029,P 〈0.01;tv =2.061,P 〈0.05;tⅥ =4.265,P 〈0.01）.The neuron dendrites length of nNOS positive neurons in visual cortex 17 in 4-week rats of monocular deprived group was decreased obviously than 4-week rats of normal group before reverse suture treatment （ t = 4.056 ,P 〈 0.01 ）. The neuron cross area of visual cortex 17 area in 48-day rats of monocular deprived group was significant decreased than 6-week rats of normal group （ t = 3. 056,P 〈0.05 ）. Conclusion The expression of nNOS might have spatial and time specificity. It implies that NO participates i
出处
《眼科研究》
CSCD
北大核心
2009年第3期206-210,共5页
Chinese Ophthalmic Research
关键词
神经型一氧化氮合酶
单眼剥夺
反缝治疗
视皮层17区
视觉发育
nerve nitric oxide synthetase
monocular deprivation
reverse suture treatment
visual cortex 17 area
visual development
