发育期不同阶段大鼠视皮层局部场电位振荡活动特性的研究

发布时间：2018-03-13 00:34

本文选题：大鼠　切入点：初级视皮层　出处：《天津医科大学》2011年硕士论文　论文类型：学位论文

【摘要】：目的本研究旨在从神经元集群水平研究大鼠初级视皮层(V1区)局部场电位(local field potential, LFP)振荡的特性,探讨大鼠初级视皮层的层间特异性；比较出生后第2、3周和成年大鼠V1区LFP的特性,观察视皮层发育过程中L5(10-20Hz)频段LFP的变化,以期阐述发育期不同阶段大鼠视皮层自发LFP振荡活动的特性。以此来探讨抑制性成分在视觉可塑性中的作用。方法取健康Wistar大鼠62只,根据其处于发育期的不同阶段分为三组：发育关键期初期组(P14-16)15只,发育关键期高峰期组(P20-22)22只,发育成熟期组(P60)25只。应用细胞外记录技术,记录麻醉状态下发育期不同阶段大鼠V1区LFP振荡活动。利用快速傅立叶转换(Fast Fourier Transformation,FFT)获得功率频谱图(Power Spectrum),分析各组V1区2+3层(L2/3)和第5层(L5)低频段和(10-20Hz)高频段的功率成分(Power)。根据公式：功率比(Power Ratio)=(P high+Plow)/(P high-Plow),求得各个记录位点的Power Ratio,并绘制Power Ratio与皮层深度分布散点图。分别比较三组间L5(10-20Hz)频段Power和Power Ratio差异,绘制简单条形图。观察大鼠V1区LFP的层间差异在不同发育期的变化规律。结果 1.发育关键期初期大鼠V1区LFP振荡特性采集到P14-16大鼠V1区28个记录位点自发锋电位反应良好的LFP信号。该组大鼠V1区LFP振荡活动表现出层间差异。L2/3以(2-5Hz)低频振荡为主,L5除了(2-5)Hz频段存在Power峰值以外,在(10-20)Hz频段也出现了强烈的振荡活动。Power Ratio与皮层深度相关性分析显示：两者呈正相关(r=0.527,P=0.007)有统计学意义,回归方程为：y=-1.293+0.001x。快速振荡(高Power Ratio)主要集中在深层：L5Power Ratio集中在-0.3-0.6之间,而L2/3则小于-0.3。 2.发育关键期高峰期大鼠V1区LFP振荡特性采集到P20-22大鼠V1区25个记录位点自发锋电位反应良好的LFP信号。其自发LFP未观察到层间差异,记录各层都以(2-5)Hz低频振荡为主。对皮层深度与Power Ratio绘制散点图并进行相关分析,结果显示两者没有明显相关性(r=0.07,P=0.733)。 3.发育成熟期大鼠V1区LFP振荡特性采集到P60大鼠V1区24个记录位点自发锋电位反应良好的LFP信号。该层自发LFP振荡表现与关键期初期组相似存在层间差异,L2/3以(2-5Hz)低频振荡为主,L5除了低频段功率频谱存在高峰以外,在(10-20Hz)高频段也有较强的振荡活动。对皮层深度与Power Ratio绘制散点图并进行相关分析,结果显示两者呈正相关(r=0.663,P=0.000)有统计学意义。其回归方程为：y=-0.649+0.001x。 4.发育期不同阶段V1区LFP特性的比较采集到三组V1区77个记录位点自发锋电位反应良好的LFP信号。三组V1区L5自发LFP的Power值和Power Ratio值分别进行单因素方差分析。统计结果显示：关键期初期组和成年组L5Power相比差异无统计学意义(P=0.828),两组Power Ratio相比差异也无统计学意义(P=0.551)。而关键期高峰组和其他两组比较差异均有统计学意义(P=0.000)。结论 1.发育关键期初期和成熟期大鼠V1区的自发局部场电位振荡存在层间差异。 2.V1区第5层高频段LFP振荡活动在发育期不同阶段表现不同。 3.实验结果与发育关键期GABA能理论吻合,支持抑制性成分在视皮层发育可塑性关键期中的作用。
[Abstract]:objective
The purpose of this study is to research from the cluster level of neurons in the rat primary visual cortex (area V1) local field potential (local field potential, LFP) oscillation characteristics of the primary visual cortex of rats between the layers of specificity; characteristics of 2,3 week and LFP V1 adult rats compared after birth, the development of visual observation in the cortex of L5 (10-20Hz) LFP to change frequency, this development stage characteristics of visual cortex LFP spontaneous oscillatory activity in different stages of rats. In order to investigate the inhibitory component of visual plasticity in the role.
Method
62 healthy Wistar rats at different stages in the developmental stages were divided into three groups: the early development of the critical period group (P14-16) 15, the critical period of growth peak group (P20-22) 22, mature stage group (P60) 25. Application of extracellular recording technique to record under anesthesia state development at different stages of rat V1 LFP oscillatory activity. Conversion by fast Fu Liye (Fast Fourier Transformation, FFT) power spectrum (Power Spectrum), V1 was analyzed 2+3 layer (L2/3) and fifth (L5) and low frequency (10-20Hz) power frequency components (Power). According to the formula: power ratio (Power Ratio) = (P / high+Plow) (P high-Plow), to achieve the various recording sites of Power Ratio and Power Ratio and cortex depth distribution of scatter diagram drawing. Were compared between the three groups (L5 10-20Hz) and Power Ratio Power frequency difference, draw a simple bar chart. Observe the LFP V1 region in the layer The variation of the difference between different developmental stages.
Result
1. LFP oscillation in V1 region of rats at the early stage of development
Collected 28 recording sites of P14-16 in V1 area of rats with spontaneous LFP spike signal response is good. The rats in group V1 LFP showed oscillatory activity difference between layers of.L2/3 (2-5Hz) with low frequency oscillation, in addition to L5 (2-5) Hz band Power peak, at (10-20) Hz band also appeared the correlation between.Power Ratio and cortical oscillation depth strongly analysis showed that they were positively correlated (r=0.527, P=0.007) were statistically significant, the regression equation is: y=-1.293+0.001x. fast oscillation (high Power Ratio) mainly concentrated in the deep L5Power Ratio concentrated in -0.3-0.6, while the L2/3 is less than -0.3.
2. LFP oscillation in V1 region of rats during peak period of developmental critical period
Collected 25 recording sites of P20-22 in V1 area of rats with spontaneous LFP spike signal response is good. The spontaneous LFP no observed difference between layers, each layer to record (2-5) Hz of low frequency oscillation. The cortical depth and Power Ratio scatter diagram and correlation analysis, results showed that there was no significant correlation between the two researchers (r=0.07, P=0.733).
3. LFP oscillation in V1 region of mature rats
Collected 24 recording sites of P60 in V1 area of rats with spontaneous LFP spike signal response is good. The LFP layer and the critical period of spontaneous oscillation period were similar to the existing difference between layers, L2/3 (2-5Hz) with low frequency oscillation, L5 low frequency power spectrum peak in addition to outside, in the high frequency (10-20Hz) is oscillatory activity is strong. The cortical depth and Power Ratio scatter diagram and correlation analysis showed a positive correlation (r=0.663, P=0.000) were statistically significant. The regression equation is: y=-0.649+0.001x.
Comparison of LFP characteristics in V1 region at different stages of development stage 4.
The collected 77 records were three V1 in group LFP spontaneous spike signal response is good. The three group of V1 L5 and Power LFP spontaneous Power value Ratio value respectively by single factor variance analysis. The statistical results show that the critical period of the early group and adult group L5Power had no significant difference between the two groups (P= 0.828). Power Ratio compared with no significant differences (P=0.551). And the peak of critical period group and other two groups were statistically significant (P=0.000).
conclusion
1. the spontaneous local field potential oscillations in the V1 region of the early and mature stage of the developmental critical period exist in the interlayer difference.
The LFP oscillations in the fifth layer of high frequency section of the 2.V1 region are different at different stages of development.
3. the results of the experiment coincide with the theory of GABA at the critical stage of development, supporting the role of the inhibitory components in the plastic critical stage of the development of the visual cortex.

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R339.141

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