大鼠视皮层锥体神经细胞被动膜特性随视觉发育的变化  

Development of passive membrane properties of cone neurons with visual development at visual cortex in rats

作　　者：王蕊[1] 史学锋[1] 程文博[1] 张腾月[1] 赵堪兴[1] 

机构地区：[1]天津市眼科医院,天津市眼科学与视觉科学重点实验室,天津市眼科研究所,天津医科大学眼科临床学院,天津市300020

出　　处：《眼科新进展》2016年第10期906-909,914,共5页Recent Advances in Ophthalmology

基　　金：国家自然科学基金资助(编号:30730099)~~

摘　　要：目的 研究Wistar大鼠初级视皮层第Ⅱ/Ⅲ层锥体神经元被动膜特性在视觉发育不同时期的变化规律及其影响因素。方法 选取出生后14~60 d的Wistar大鼠,采用正常饲养和完全黑暗饲养两种方式,将其按视觉发育的不同阶段各分为五组（P13-15组、P16-20组、P25-27组、P30-35组、P55-60组）,在离体脑片上应用膜片钳全细胞记录技术,观察视觉发育不同阶段以及不同饲养条件下神经元被动膜特性的变化规律。结果 P13-15组与P25-27组在正常饲养条件下的时间常数分别为（28.79±6.68）ms、（21.51±4.64）ms,在暗饲养条件下分别为（38.71±6.04）ms、（19.13±7.35）ms,差异均有统计学意义（均为P〈0.05）;P13-15组中暗饲养的时间常数明显大于正常饲养（28.79±6.68）ms,差异有统计学意义（P〈0.05）,而P25-27组中暗饲养与正常饲养的时间常数分别为（19.13±7.35）ms、（21.51±4.64）ms,差异无统计学意义（P〉0.05）。正常饲养条件下,P13-15组与P16-20组的膜电阻分别为（131.03±40.78）MΩ、（100.47±22.94）MΩ,差异有统计学意义（t=2.59,P〈0.05）,P30-35组与P55-60组的膜电阻分别为（82.38±20.43）MΩ、（66.25±18.93）MΩ,差异有统计学意义（t=2.13,P〈0.05）。时间常数和膜电阻具有正相关关系（r=0.275,P〈0.05）。结论 正常和暗饲养两种条件下,大鼠初级视皮层第Ⅱ/Ⅲ层锥体神经元的被动膜特性都具有随视觉发育而逐渐下降的趋势,受视觉经验的影响较小,进而推测年龄是影响被动膜特性的决定性因素。Objective To study the change rules and influence factors of passive membrane properties of cone neurons of primary visual cortex layer 1] /IlI in rats at dif- ferent visual development periods. Methods Wistar rats at postnatal 14 - 50 days （P14-50） were separately raised by normal way and completely darkness way, then each group was further divided into five groups （ P13-15, P16-20, P25-27, P30-35, P55- 60）, and whole-cell recordings was performed at brain slice of visual cortex in order to explore the change rules of passive membrane properties. Results The time constant in P13-15 group and P25-27 group under normal rising condition were （28.79 ±5.68）ms and （21.51±4.54） ms,wtfich under dark rising condition were （38.71± 6.04）ms and （ 19.13±7.35 ） ms ,there were statistical differences （ all P 〈 0.05 ）. The time constant in P13-15 group under dark rising condition was more than that under normal rising condi- tion （P 〈 0.05 ）, but there was no statistical difference of P25-27 group （P 〉 0.05 ）. The membrane resistance in P13-15 group and P16-20 group under normal rising condition were （ 131.03± 40.78 ） M and （ 100.47 ± 22.94 ） M, there was statistical difference （ t = 2.59 ,P 〈 0.05 ）, which in P30-35 and P55-60 groups were （ 82.38 ± 20.43 ） M and （66.25 ± 18.93 ） M, and there was statistical difference （ t = 2. 13, P 〈 0.05 ）. The time constant and membrane resistance was positive correlated （ r = 0.275 ,P 〈 0.05 ）. Conclusion In both two rising ways, the time constant and membrane resistances are gradually declined with visual development, the passive membrane properties of cone neurons of primary visual cortex layer Ⅱ/Ⅲ in rats are little affected by the visual ex- perience, which speculated that age may be the key factor.

关 键 词：被动膜特性 时间常数 膜电阻 

分 类 号：R774.6[医药卫生—眼科]