目的:研究视觉发育期脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)在正常和剥夺弱视大鼠模型视皮层表达变化规律。方法:SD大鼠眼睑缝合行视觉剥夺,取大脑视皮层行尼氏染色进行形态学分析,用免疫组织化学SABC技术染色和计算机图形分析BDNF在P14,P21,P45,P120,MD鼠同侧视皮层17区的表达。结果:与正常组比较MD弱视大鼠视皮层神经元数目略减少,细胞突起数目未见明显减少,但神经元体积不一致,神经元体积变小、细胞核着色加深。BDNF在正常视皮层表达变化同视觉发育期一致,P14~P21表达渐强,P21表达高峰,P45表达降低,P120呈低表达,P14与P21组间差异有非常显著统计学意义(P<0.01),P14与P45组间差异无显著统计学意义(P>0.05),P45与P120组间差异有显著统计学意义(P<0.05);BDNF在MD弱视组视皮层呈持续低表达,与正常组比较具有非常显著的差异性(P<0.01)。结论:BDNF在视皮层的表达变化同视觉发育期相一致,其参与视觉发育关键期突触塑形,为弱视形成的分子学基础之一。

AIM:To observe and research the expression of brain-derived neurotrophic factor(BDNF)in visual cortex of normal and monocular form deprivation amblyopia rats.METHODS:Model of monocular form deprivation amblyopia was established in SD rats by eyelid suture.Then the visual cortex was extracted and performed morphological analysis depending on Nissl’s dyeing,the expression of BDNF in visual cortex of P14,P21,P45,P120 MD rats was analyzed by immunohistochemistry SABC technique and computer graphics.RESULTS:Compared with the normal group,the number of neurons in visual cortex of MD rats was slightly reduced,neurons volume decreased,nuclear staining deepened.Expression of BDNF in normal visual cortex was consistent with visual development,P14-P21 the expression increased gradually,P21 reached peak,P45 decreased and P120 showed low expression,there was obvious statistical significance between P14 group and P21 group(P<0.01),and there was statistical significance between P45 group and P120 group(P<0.05);the BDNF kept low expression in visual cortex of MD amblyopia group,there was significant difference compared with the normal group(P<0.01).CONCLUSION:The expression of BDNF in visual cortex is consistent with the development of visual,it participates in formed synaptic styling in critical period of visual development,it is the molecular basis for amblyopia formation.

R778.11