大鼠海马CA3区神经元和星形胶质细胞三维结构重塑

Three-dimensional structural reconstruction of the neurons and astrocytes in rat hippocampal CA3 area

目的观察大鼠海马CA3区神经元锥体细胞及其周围星形胶质细胞(AST)的分布,重塑两者之间的三维构象。方法采用脑片膜片钳全细胞记录、细胞内荧光黄(LY)染色、免疫荧光和激光共聚焦显微镜检查(LSCM)相结合的技术。结果根据放电形式的不同把海马锥体细胞分为位相型和非位相型放电神经元。LSCM下单层光学图像和三维立体重建显示许多AST紧密围绕在LY染色锥体细胞周围并形成紧密接触。2类神经元与AST形成接触的部位存在区别。非位相型放电神经元的树突和胞体周围都有许多AST形成接触的部位在,而位相型放电神经元则仅位于树突。结论不同特性海马神经元周围AST的空间分布可能存在差异。

Objective To observe the distribution of the pyramidal neurons and the surrounding astrocytes in rat hippocampal CA3 area and reconstruct their three-dimension structure. Methods Whole-cell patch-clamp recording of the brain slices, intracellular staining with Lucifer yellow, glial fibrillary acidic protein (GFAP) immunofluorescence, and confocal laser scanning microscopy were utilized in this study. Results According to the firing patterns, the hippocampal pyramidal neurons were classified into phasic or non-phasic firing neurons. Monolayer scanning and three-dimensional reconstruction showed that many astrocytes aggregated in tight clusters around the pyramidal neurons positive for Lucifer yellow staining, forming close contact. The two types of neurons contacted the astrocytes in different manners. Surrounding the cell body and dendrites of the non-phasic firing neurons, many astrocytes were seen to form contact with the neurons, whereas the phasic firing neurons formed contact with the astrocytes through the dendrites. Conclusion The spatial distribution of the astrocytes surrounding different types of the hippocampal neurons may differ.