猫斜视性弱视治疗前后视皮质17区神经生长因子的表达

The difference of nerve growth factor(NGF)expression in visual cortex 17 area before and after occlusion the non-deviated eye in strabismus amblyopic cats

目的 观察斜视性弱视猫治疗前后视皮质 (VisralCortex ,VC) 17区神经生长因子(NGF)表达改变 ,探讨神经生长因子与视觉发育可塑性的联系。方法 普通 4周龄家猫 18只 ,随机分为正常对照组、斜视组和斜视治疗组 ,每组各 6只 ,后两组 4周龄时行右眼外直肌切断术 ,术后 4周经P -VEP检测确定形成弱视后立即将治疗组 6只猫行对侧眼睑暂时缝合。三组猫全部于 12周龄处死 ,取右脑半球VC17区脑组织 ,应用免疫组织化学染色法观察 17区NGF免疫阳性细胞密度。结果 斜视组与正常组相比 :免疫阳性细胞数量明显减少 (P <0 0 5 ) ,P -VEP的P1波潜时延迟 ,波幅降低 ;治疗组和斜视组相比 ,免疫阳性细胞增加 (P <0 0 5 ) ,P1波潜时缩短 ,波幅增大。结论 斜视性弱视猫VC17区NGF表达特性发生改变 ,通过遮盖对侧眼 ,增加弱视眼的视觉信息输入量 ,NGF表达增加 ,和P -VEP的改变相符合 ,遮盖治疗使实验猫弱视眼的视功能得到一定的改善。NGF作为一种细胞功能的调控因子 ,在视觉系统发育的可塑性方面发挥重要作用。

Objective To observe the changes of NGF expression in visual cortex (VC)before and after occlusion of the non-deviated eye in strabismus amblyopic cats,and to investigate the relation between NGF and plasticity of visual system.Methods Eighteen normal kittens (about 4 weeks old)were divided into three groups randomly.Twelve kittens were deduced convergent strabismus by cutting the external rectus muscle of right eyes in 4 weeks age,six of them(treated groups)were occluded in 8 weeks age.All kittens were perfused in 12 weeks age.P-VEP was recorded every 4 weeks.Results The number density(ND)of NGF-immunoreactive cells in normal kittens was higher than in strabismus and occluded kittens.P-VEP data of strabismus kittens was abnormal.But occluding the non-deviated eye can improve the number density(ND)of NGF-immunoractive cells and make P-VEP data incline to normal.Conclusions NGF expression in 17 area of VC decreased in strabismus amblyopic cats and improved after occlusion of the non-deviated eyes;In cortical period of visual development;NGF has important role in manipulate the plasticity of visual system.