摘要： 目的·在小鼠全脑范围定量分析支配初级视皮层的丘脑背外侧核神经元亚群的直接输入神经元。方法·向C57BL/6J雄性小鼠初级视皮层注射表达小麦胚芽凝集素和Cre重组酶融合蛋白的腺相关病毒，同时向丘脑背外侧核注射Cre重组酶依赖的分别表达禽类肉瘤/白血病病毒包膜蛋白受体TVA和狂犬病毒糖蛋白的假性狂犬病毒辅助腺相关病毒。28 d后，向初级视皮层注射假性狂犬病毒。待假性狂犬病毒携带的绿色荧光蛋白在丘脑背外侧核神经元亚群的上游输入神经元中充分表达后，即7 d后，收集小鼠脑部样本，并制作冰冻切片。荧光显微镜下观察支配初级视皮层的丘脑背外侧核神经元亚群的输入神经元在脑内的分布情况，并使用高通量解剖数据分析软件进行定量分析。结果·荧光显微镜观察及定量分析结果发现，支配初级视觉皮层的丘脑背外侧核神经元亚群的输入神经元在皮层、间脑和中脑均有分布，分别占全脑绿色荧光标记神经元总数的（58.1±4.8）%、（23.2±0.9）%和（15.3±4.0）%。在皮层区域，输入神经元分布最多的区域是躯体运动皮层、视皮层和躯体感觉皮层；在前额叶皮层和中间联合皮层也有大量输入神经元分布；在感觉皮层中，输入神经元的胞体主要分布在第5层和第6层。结论·支配初级视觉皮层的丘脑背外侧核神经元亚群的输入神经元在全脑分布广泛，其中多数位于皮层区。
关键词: 丘脑背外侧核, 初级视皮层, 全脑输入图谱, 小鼠, 假性狂犬病毒 Abstract: Objective·To analyze the whole-brain inputs to the projection neurons in the lateral dorsal nucleus (LD) of thalamus innervating primary visual cortex (V1) in mice.
Methods·The adeno-associated virus (AAV) vectors expressing the fusion protein of wheat germ agglutinin and Cre recombinase (Cre) were injected into V1 of C57BL/6J male mice, and the AAV vectors with Cre-inducible expression of avian sarcoma/leukosis virus envelope glycoprotein receptor TVA and rabies glycoprotein were injected into LD, respectively. Twenty-eight days later, the pseudotyped rabies virus (RV) was injected into V1. After the full expression of RV-mediated green fluorescent protein in the infected input neurons of LD, i.e., 7 d later, brain samples were collected and frozen sections were made. The whole-brain distribution of RV-labeled neurons were observed under fluorescence microscope, and quantitative analysis was performed by using high-throughput anatomical data analysis software.
Results·Through fluorescence microscope and quantitative analysis, the whole-brain map showed that the inputs of LD neurons innervating V1 mainly came from cortex, middle brain and inter brain, accounting for (58.1±4.8)%, (23.2±0.9)% and (15.3±4.0)% of the total number of GFP-labeled neurons in the whole brain, respectively. In the cortex, the areas with the most input neurons were somatomotor area, visual area and somatosensory area. A large number of input neurons were also distributed in prefrontal cortex and medial commissural cortex. In the sensory cortex, the cell bodies of the inputs were mainly distributed in the fifth and sixth layers.
Conclusion·The direct inputs of LD neuron subgroups innervating V1 in mice are widely distributed throughout the brain, most of which are located in the cortex.
Key words: lateral dorsal nucleus of thalamus, primary visual cortex, whole-brain inputs, mouse, pseudotyped rabies virus PDF全文下载地址:
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