双眼形觉剥夺对大鼠视皮层神经元γ-氨基丁酸电流的影响  

Effects of binocular form deprivation on the properties of gamma-aminobutyric acid currents of rat visual cortical neurons

作　　者：秦伟[1] 阴正勤[1] 王仕军[1] 赵妍君[2] 

机构地区：[1]第三军医大学西南眼科医院,重庆400038 [2]美国耶鲁大学生理学实验室

出　　处：《中华眼科杂志》2005年第1期37-40,共4页Chinese Journal of Ophthalmology

基　　金：国家杰出青年科学基金资助项目(30025014)

摘　　要：目的探讨双眼形觉剥夺对大鼠视觉发育可塑性关键期内视皮层神经元γ氨基丁酸电流的影响。方法采用脑片膜片钳全细胞记录技术,记录出生后14、21和28d正常、双眼形觉剥夺和去除剥夺大鼠视皮层神经元兴奋性突触后电流。然后在人工脑脊液中同时加入D,L2氨基5磷酸基戊酸50μmol/L和氰基7硝基喹啉2,3二酮20μmol/L,分离出γ氨基丁酸受体介导的成分电流,分析其电学特性。结果随着周龄增加,正常组大鼠视皮层神经元的抑制性突触后电流的下降时间和峰值显著变长和增大(P<005);而双眼形觉剥夺组内无明显变化(P>005);去除剥夺后1周,大鼠视皮层神经元抑制性突触后电流的下降时间和峰值增大(与双眼形觉剥夺组生后4周比较,P<005)。各组内,上升时间无明显变化(P>005)。结论随着视觉发育,正常大鼠视皮层神经元的γ氨基丁酸受体介导的抑制性突触传递增强,双眼形觉剥夺抑制这一变化,恢复视觉输入后可以逆转。(中华眼科杂志,2005,413740)Objective To investigate the effects of binocular form deprivation on the properties of inhibitory synaptic transmission of rat visual cortical neurons during the critical period of visual development. Methods We recorded the postsynaptic currents in visual cortex slices of normal, binocular form deprived and deprivation-removed rats at postnatal days 14, 21 and 28 with the use of whole-cell patch recording, and recorded gamma-aminobutyric acid currents by adding D, L-2-amino-5-phosphonovalerate (50 μmol/L) and 6-cyano-7-nitroquinoxaline-2,3-dione (20 μmol/L) to artificial cerebrospinal fluid. The electrophysiological properties were also analysed. Results The decay time and peak value of inhibitory postsynaptic currents of normal rat visual cortical neurons became larger with age(P<0.05), but not in binocular form deprived group(P>0.05). The decay time and peak value of inhibitory postsynaptic currents became large in deprivation-removed rats at postnatal days 28(P<0.05). The rise time did not change markedly in all groups. Conclusion With visual development, the synaptic transmission of visual cortical neurons in normal rats is strengthened, but it can be inhibited by binocular form deprivation and recovered by visual input.

关 键 词：双眼 形觉剥夺 视皮层 神经元 大鼠 视觉发育 正常 硝基 去除 磷酸 

分 类 号：R77[医药卫生—眼科]