Day N C, Shaw P J, McCormack A L, Craig P J, Smith W, Beattie R, Williams T L, Ellis S B, Ince P G, Harpold M M, Lodge D, Volsen S G
MRC Neurochemical Pathology Unit, Newcastle General Hospital, Newcastle upon Tyne, U.K.
Neuroscience. 1996 Apr;71(4):1013-24. doi: 10.1016/0306-4522(95)00514-5.
The distribution of voltage-dependent calcium channel subunits in the central nervous system may provide information about the function of these channels. The present study examined the distribution of three alpha-1 subunits, alpha 1A, alpha 1B and alpha 1E, in the normal human hippocampal formation and parahippocampal gyrus using the techniques of in situ hybridization and immunocytochemistry. All three subunit mRNAs appeared to be similarly localized, with high levels of expression in the dentate granule and CA pyramidal layer. At the protein level, alpha 1A, alpha 1B and alpha 1E subunits were differentially localized. In general, alpha 1A-immunoreactivity was most intense in cell bodies and dendritic processes, including dentate granule cells, CA3 pyramidal cells and entorhinal cortex pre-alpha and pri-alpha cells. The alpha 1B antibody exhibited relatively weak staining of cell bodies but stronger staining of neuropil, especially in certain regions of high synaptic density such as the polymorphic layer of the dentate gyrus and the stratum lucidum and radiatum of the CA regions. The alpha 1E staining pattern shared features in common with both alpha 1A and alpha 1B, with strong immunoreactivity in dentate granule, CA3 pyramidal and entorhinal cortex pri-alpha cells, as well as staining of the CA3 stratum lucidum. These findings suggest regions in which particular subunits may be involved in synaptic communication. For example, comparison of alpha 1B and alpha 1E staining in the CA3 stratum lucidum with calbindin-immuno-reactivity suggested that these two calcium channels subunits may be localized presynaptically in mossy fibre terminals and therefore may be involved in neurotransmitter release from these terminals.
电压依赖性钙通道亚基在中枢神经系统中的分布可能为这些通道的功能提供信息。本研究采用原位杂交和免疫细胞化学技术，检测了正常人海马结构和海马旁回中三种α-1亚基（α1A、α1B和α1E）的分布。所有三种亚基的mRNA定位似乎相似，在齿状颗粒层和CA锥体细胞层中表达水平较高。在蛋白质水平上，α1A、α1B和α1E亚基的定位存在差异。一般来说，α1A免疫反应性在细胞体和树突过程中最为强烈，包括齿状颗粒细胞、CA3锥体细胞和内嗅皮层的前α和原α细胞。α1B抗体对细胞体的染色相对较弱，但对神经毡的染色较强，尤其是在某些突触密度高的区域，如齿状回的多形层以及CA区的透明层和辐射层。α1E的染色模式与α1A和α1B都有共同特征，在齿状颗粒细胞、CA3锥体细胞和内嗅皮层原α细胞中有强烈的免疫反应性，以及CA3透明层的染色。这些发现提示了特定亚基可能参与突触通讯的区域。例如，将CA3透明层中α1B和α1E的染色与钙结合蛋白免疫反应性进行比较，表明这两种钙通道亚基可能位于苔藓纤维终末的突触前，因此可能参与这些终末的神经递质释放。
