触须感觉信息输入减少诱导桶状皮层锥体神经元和GABAergic神经元功能的可塑性

发布时间：2018-05-05 22:15

本文选题：桶状皮层 + GABA能神经元　；参考：《蚌埠医学院》2012年硕士论文

【摘要】：目的：建立小鼠触须感觉信息输入减少的动物模型，分析触须感觉信息输入减少后，桶状皮层（Barrel Cortex）锥体神经元和GABA能神经元内在特性和神经元群集发放动作电位编码功能的变化，探讨神经网络功能的可塑性机制。方法：1.小鼠触须感觉信息输入减少模型的建立：将FVB-Tg（Gad GFP）4570Swn/J小鼠右侧嘴角部全部触须修剪至小于1mm，每24小时修剪一次，从出生后7天开始修剪持续到出生后17天。 2.在上述处理10天以后，应用T迷宫实验检测小鼠嗅觉功能变化，实验中小鼠移动到食物一侧的成功率作为鉴别其嗅觉功能上调的指标。 3.膜片钳电生理实验：取出生1周后小鼠，连续造模后10天，用异氟烷吸入麻醉，迅速将大脑分离，做冠状切片（400μm），然后将脑片置于氧合的人工脑脊液(ASCF)中，25C下孵育1-2小时后转移至灌流槽，在31C下对脑片进行灌流；采用IR-DIC光学显微镜(Nikon E600FN)荧光显微镜定位大脑桶状皮层绿色荧光蛋白标记的GABA能神经元和锥体神经元；运用Axoclamp-200B放大器，电流钳模式全细胞记录方法记录大脑桶状皮层GABA能神经元和锥体神经元的动作电位，测量其发放容量及阈电位(threshold potentials, Vts)，电压钳模式全细胞记录方法采集GABA能神经元sIPSCs（自发性抑制性突触后电流）包括电流间距（Interval of Events，IE）和电流幅度（Amplitude）数据，信号数据输入Clampex10.1进行处理分析。结果：1.造模组小鼠对食物的正确选择成功率明显高于正常组小鼠；2.应用膜片钳方法，，电流钳模式实验结果发现，与正常组相比，造模组桶状皮层锥体神经元群集发放动作电位的发放容量显著增加，动作电位间距ISI缩短(P0.05)，阈电位(Vts)降低(P0.05)；GABA能神经元群集发放动作电位的发放容量显著降低，动作电位间距ISI延长(P0.05)，阈电位(Vts)升高(P0.05)；3.电压钳模式实验结果发现，与正常组相比，造模组桶状皮层GABA能神经元的sIPSCs的电流间距延长（P0.05），电流幅度降低(P0.05)。结论：1.触须感觉信息输入减少后，小鼠嗅觉功能上调；2.小鼠触须感觉信息输入减少，桶状皮层锥体神经元功能上调，GABA能神经元功能下调；桶状皮层兴奋性神经元功能上调和抑制性神经元功能下调导致神经网络整体功能增强。
[Abstract]:Objective: to establish an animal model of decreased sensory information input in mouse tentacles, and to analyze the reduction of sensory information input in mouse tentacles. The intrinsic characteristics of pyramidal neurons and GABA neurons in barrel-Cortex-pyramidal neurons and the changes in the coding function of the action potential of neuron clusters were studied to explore the plasticity mechanism of neural network function. Method 1: 1. Establishment of a model for reducing the input of sensory information in mouse tentacles: all the tentacles in the right mouth corner of FVB-Tg(Gad GFP)4570Swn/J mice were trimmed to less than 1 mm, trimmed every 24 hours, from 7 days after birth to 17 days after birth. 2. After 10 days of treatment, T maze test was used to detect the changes of olfactory function in mice. The success rate of mice moving to one side of food was used as an index to identify the up-regulation of olfactory function. 3. Patch clamp electrophysiological experiment: the mice were taken out one week after birth. After 10 days of continuous modeling, isoflurane was inhaled to anesthetize the brain, and the brain was separated quickly. The brain slices were incubated at 25C for 1-2 hours and then transferred to the perfusion trough. The slices were perfused at 31C, then the brain slices were incubated in the oxygenated artificial cerebrospinal fluid (ASCF) for 1 to 2 hours. The IR-DIC optical microscope and Nikon E600FN fluorescence microscope were used to locate the GABA neurons and pyramidal neurons labeled with green fluorescent protein (GFP) in the barrelled cortex, and the Axoclamp-200B amplifier was used. The action potentials of GABA neurons and pyramidal neurons in the barrelled cortex were recorded by current clamp mode whole-cell recording method. The release capacity, threshold potential, voltage clamp mode and voltage clamp mode whole-cell recording were used to collect the data of sIPSCs (spontaneous inhibitory postsynaptic currents) including current spacing interval of events IEE and amplitude of current Amplitudee. The signal data is input into Clampex10.1 for processing and analysis. The result is 1: 1. The success rate of food selection in model group was significantly higher than that in normal group. By using patch clamp method and current clamp mode experiment, it was found that compared with the normal group, the discharge capacity of the pyramidal pyramidal neurons in the bucket cortex in the model group was significantly increased. Action potential spacing (ISI) shortened P0.05N and threshold potential (VtsS) decreased significantly the release capacity of P0.05GABA-neuron cluster action potential (P0.05N). The interval of action potential (ISI) was prolonged (P0.05N), and the threshold potential (Vts) increased (P0.05) ~ (3). The results of voltage clamp mode experiment showed that compared with the normal group, the sIPSCs current spacing of the barrelled cortical GABA neurons in the model group was prolonged (P0.05) and the current amplitude was decreased (P0.05). Conclusion 1. The olfactory function of mice was upregulated by tactile sensory information input. The sensory information input of mouse tentacles decreased, the function of pyramidal neurons in the bucket cortex increased and the function of GABA neurons down-regulated, while the function of excitatory neurons in the barrelled cortex and the down-regulation of the inhibitory neurons resulted in the enhancement of the overall function of the neural network.
【学位授予单位】：蚌埠医学院
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R338.1

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