正常和剥夺性弱视大鼠视皮质NOS阳性神经元的生后发育变化

Postnatal developmental changes of NOS-positive neurons in the visual centres of normal and deprivation amblyopia rats

目的 :探讨NO参与正常视觉发育可塑性的分子机制及视觉剥夺对NO的表达所产生的影响。方法 :正常和剥夺性弱视大鼠分别在不同时限 (P14～P4 5 )测定视皮质 17区的NOS阳性神经元组织切片下的表达。结果用光镜下计数和计算机图形分析系统得出。结果 :正常大鼠视皮质 17区中的NOS阳性神经元 ,P14时数量最多 ,到P2 1时神经元胞体截面积最大 ,树突分枝最复杂。剥夺对侧与同期正常鼠及剥夺同侧比较无显著性差异。结论 :在视觉发育关键期 ,NOS在正常发育大鼠及剥夺性弱视大鼠视觉中枢中成短暂的高水平表达。单眼剥夺不会影响NOS在皮质 17区的表达。

Objective:To study the molecular mechanism of NO participting the plasticity of normal visual development and the effect of visual deprivation on expression of NO.Methods:The VC of rats were sliced coronally at the ages from postnatal 14 days(p14)to P45,and the sections were processed for nicotinamide adenine dinucleotide phsphate diaphorase(NADPH-d)histochemical staining.Changes in number,cell body area and total length of dendrites of NOS positive neurons in VC from normal groups and monocular deprivation groups were observed with microscope and analysed by Computer Image Analysis System.Results:The number of NOS-positive neurons in VC of normal rats reached a peak at P14,and gradually reduced.The area of neurons are largest,the dendrites of neuones are more compex and longer in P21.Conclusion:NOS exhibits a transient expression on the high level.Monocular deprivation has not influenced the expression of NOS in VC.