大鼠视皮层锥体神经元静息膜电位随年龄变化趋势

发布时间：2018-05-05 23:22

本文选题：静息膜电位 + 视皮层　；参考：《天津医科大学》2012年硕士论文

【摘要】：目的研究正常光线条件下饲养及暗饲养条件下,不同年龄段大鼠视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位变化趋势,比较两组大鼠视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位的差异。方法将正常光线条件下饲养wistar大鼠分为五个年龄段,即p10-12d(睁眼前组),p14-16d(前关键期组),p19-21d(关键期组),p35-40d(后关键期组)及大于p60d(成年组),应用红外微分干涉相差显微镜(IR-DIC)结合电耦合式摄像机(CCD-Camera)可视法膜片钳全细胞模式下进行实验,记录健康wistar大鼠离体脑片视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位。将暗饲养的wistar大鼠分为三个年龄段,即p10-12d(睁眼前组),p14-16d(前关键期组),p19-21d(关键期组),应用红外微分干涉相差显微镜(IR-DIC)结合电耦合式摄像机(CCD-Camera)可视法膜片钳全细胞模式下进行实验,记录暗饲养wistar大鼠离体脑片视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位,并与相对应年龄段健康wistar大鼠静息膜电位进行比较。结果 1.正常光线条件下饲养的各组大鼠视皮层Ⅲ层锥体神经元静息膜电位为：pl0-12d(睁眼前组)(-45.665±6.848)mv,p14-16d(前关键期组)(-67.174±6.909)mv,p19-21d(关键期组)(-72.922±5.302)mv,p35-40d(后关键期组)(-77.294±4.361)mv,大于p60d(成年组)(-78.375±3.695)mv。随年龄增长,大鼠视皮层Ⅱ/Ⅲ层锥体神经元静息电位逐渐降低,在视觉发育关键期后,达到平台期,接近成年水平(关键期后组和成年组静息电位值无统计学意义,ANOVA,P0.05;其余组之间均有统计学差异,ANOVA,P0.05). 2.各组暗饲养大鼠视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位为：p10-12d(睁眼前组)(-53.147±4.364)mv,p14-16d(前关键期组)(-60.008±8.082)mv,p19-21d(关键期组)(-58.019±7.698)mv,p14-16d(前关键期组)视皮层Ⅱ/Ⅲ锥体神经元静息膜电位较p10-12d(睁眼前组)更负,有统计学差异(ANOVA,P=0.012,P0.05)。而p14-16d(前关键期组)及p19-21d(关键期组)的视皮层Ⅱ/Ⅲ层锥体神经元细胞的静息膜电位相比较,无统计学差异(ANOVA,P=0.454,P0.05)。 3.正常光线条件下饲养及暗饲养组大鼠在p10-12d(睁眼前组),p14-16d(前关键期组),p19-21d(关键期组)三个年龄段,视皮层Ⅱ/Ⅲ锥体神经元静息膜电位随着天龄的增加而逐渐变负,暗饲养大鼠天龄增加,视皮层Ⅱ/Ⅲ锥体神经元静息膜电位变化幅度减小,明显小于正常光线条件下饲养组大鼠。结论 1.正常光线条件下饲养组大鼠的静息电位变化趋势：当视觉发育关键期未结束时,视皮层Ⅱ-Ⅲ层锥体神经元静息膜电位随着天龄的增加逐渐变负,而当关键期过后,视皮层Ⅱ-Ⅲ层锥体神经元静息膜电位则稳定下来,达到了成熟水平。暗饲养组大鼠视皮层Ⅱ-Ⅲ层锥体神经元静息膜电位也有逐渐变负的趋势,变化幅度减小,处于未成熟水平。 2.将正常光线条件下饲养组大鼠与暗饲养大鼠的p10-12d(睁眼前组),p14-16d(前关键期组)及p19-21d(关键期组)年龄段的静息膜电位进行比较,正常光线条件下饲养组大鼠的静息膜电位变化幅度远大于暗饲养组大鼠,表明在视觉发育过程中,视觉经验是促进视觉发育成熟的关键因素。在视觉系统发育的早期阶段,为了促进自身的成熟,视觉系统对外界的刺激敏感,使锥体神经元之间形成有效的联接,有效的突触修饰也开始进行。当视觉发育关键期过后,视觉系统发育成熟,对外界刺激的敏感度降低。视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位趋于一致,形成平台期。暗饲养干扰了上述过程,视皮层Ⅱ/Ⅲ层锥体神经元静息膜电位维持在未成熟状态。
[Abstract]:objective
The change trend of resting membrane potential in the visual cortex II / III pyramidal neurons of different age rats was studied under normal light conditions under the condition of feeding and dark feeding, and the difference of resting membrane potential in the two groups of rat visual cortex II / III pyramidal neurons was compared.
Method
Wistar rats were divided into five age groups under normal light conditions, namely, p10-12d (open and front group), p14-16d (pre critical stage group), p19-21d (key stage group), p35-40d (post critical period group) and greater than p60d (adult group), using infrared differential interference phase contrast microscope (IR-DIC) combined with electrically coupled camera (CCD-Camera) visual patch clamp whole cell The resting membrane potential of the second / third pyramidal neurons in the visual cortex of healthy Wistar rats was recorded.
The dark reared Wistar rats were divided into three age groups, namely, p10-12d (front and front groups), p14-16d (pre critical stage group) and p19-21d (critical phase group). The infrared differential interference phase contrast microscope (IR-DIC) was used in conjunction with the electrically coupled camera (CCD-Camera) visual patch clamp whole cell model to record the dark feeding of the isolated brain slices of Wistar rats. Resting membrane potential of cortical II / III pyramidal neurons was compared with resting membrane potential of healthy Wistar rats at corresponding age.
Result
1. the resting membrane potential of the third layer pyramidal neurons in the visual cortex of the rats was pl0-12d (-45.665 + 6.848) MV, p14-16d (-67.174 6.909) MV, p19-21d (critical period group) (-72.922 + 5.302) MV, p35-40d (-77.294 4.361) MV, greater than that of adult (adult group) (adult group). With the increase of age, the resting potential of the pyramidal neurons in the visual cortex of the rat was gradually reduced. After the critical stage of visual development, the resting potential of V. reached the stage of platform, which was close to the adult level (the resting potential value of the post critical group and the adult group was not statistically significant, ANOVA, P0.05; the other groups were statistically different, ANOVA, P0.05).
2. the resting membrane potential of the visual cortex II / III pyramidal neurons in the dark rearing rats was p10-12d (-53.147 + 4.364) MV, p14-16d (-60.008 + 8.082) MV, p19-21d (critical phase group) (-58.019 + 7.698) MV, and p14-16d (before the key stage group) the resting membrane potential of the neurons in the visual cortex II / III pyramidal neurons was more than that of the p10-12d (open eyes). Negative, there were statistical differences (ANOVA, P=0.012, P0.05). But there was no statistical difference between the resting membrane potential of the pyramidal neurons in the visual cortex of the visual cortex (the key stage group) and the p19-21d (the key stage group). There was no statistical difference (ANOVA, P=0.454, P0.05).
3. in the normal light condition, the rats in the feeding group and the dark rearing group were in p10-12d (open eyes), p14-16d (the pre critical stage group) and the three age groups of the p19-21d (key stage group). The resting membrane potential of the neurons in the visual cortex II / III pyramidal neurons gradually became negative with the increase of the age. The age of the dark rearing rats increased and the resting membrane potential of the neurons in the visual cortex II / III pyramidal neurons changed. The extent of reduction was significantly smaller than that of rats fed normal light.
conclusion
The resting potential change trend of rats in 1. normal light conditions: when the critical stage of visual development did not end, the resting membrane potential of the pyramidal neurons of the layer II - III layer of the visual cortex gradually became negative with the increase of age, while the static membrane potential of the pyramidal neurons of the layer II - III of the visual cortex stabilized and reached the maturity level after the critical period. The resting membrane potential of the second - and third pyramidal neurons in the visual cortex of the dark feeding group also showed a gradual negative trend, with a decreasing amplitude and at an immature level.
2. compared with the resting membrane potential of p10-12d (open eyes), p14-16d (pre critical period group) and p19-21d (key stage) age group, the resting membrane potential of the rats in the normal light condition was much greater than that in the dark rearing group. Visual experience is the key factor in promoting the maturity of visual development. In the early stage of visual system development, in order to promote its maturity, the visual system is sensitive to the external stimuli, make the pyramidal neurons form an effective connection, and the effective synaptic modification begins. The sensitivity of external stimulation decreased. The resting membrane potential of the pyramidal neurons in the visual cortex was consistent and formed a platform phase. Dark feeding interfered with the above process. The resting membrane potential of the pyramidal neurons in the layer II / III of the visual cortex was maintained in the immature state.

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R77

【共引文献】