Najdzion Janusz, Wasilewska Barbara, Bogus-Nowakowska Krystyna, Robak Anna
Department of Comparative Anatomy, Faculty of Biology and Biotechnology, University of Warmia and Mazury, Plac Łódzki 3, 10-727 Olsztyn, Poland.
Department of Comparative Anatomy, Faculty of Biology and Biotechnology, University of Warmia and Mazury, Plac Łódzki 3, 10-727 Olsztyn, Poland.
J Chem Neuroanat. 2014 Sep;59-60:17-28. doi: 10.1016/j.jchemneu.2014.04.003. Epub 2014 May 6.
The purpose of this study was to describe the distribution and colocalization of cocaine- and amphetamine-regulated transcript (CART) and three calcium-binding proteins (calbindin, calretinin and parvalbumin) in each main division of the medial geniculate body (MGB) in the guinea pig. From low to moderate CART immunoreactivity was observed in all divisions of the MGB, although in most of its length only fibers and neuropil were labeled. A small number of CART immunoreactive somata were observed in the caudal segment of the MGB. The central parts of all divisions contained a distinctly smaller number of CART immunoreactive fibers relative to their outer borders, where CART fibers formed patchy clusters. As a whole, the intense CART immunoreactive borders formed a shell around the weakly CART labeled core. Double-labeling immunofluorescence showed that CART did not colocalize with either calbindin, calretinin or parvalbumin, whose immunoreactivity was predominantly restricted to perikarya. The distribution pattern of calretinin was more similar to that of calbindin than to that of parvalbumin. Calretinin and calbindin exhibited higher immunoreactivity in the medial and dorsal divisions of the MGB, where parvalbumin staining was low. In general, although parvalbumin exhibited the weakest immunoreactivity of all studied Ca(2+) binding proteins, it was most highly expressed in the ventral division of the MGB. Our results indicate that CART could be involved in hearing, although its immunoreactivity in the medial geniculate complex was not as intense as in other sensory brain regions. In the guinea pig the heterogeneous and complementary pattern of calbindin, calretinin and parvalbumin is evident, however, the overlap in staining appears to be more extensive than that seen in other rodents.
本研究的目的是描述豚鼠内侧膝状体（MGB）各主要分区中可卡因和苯丙胺调节转录物（CART）以及三种钙结合蛋白（钙结合蛋白、钙视网膜蛋白和小白蛋白）的分布与共定位情况。在MGB的所有分区均观察到低至中等强度的CART免疫反应性，不过在其大部分长度范围内，仅纤维和神经毡被标记。在MGB的尾段观察到少量CART免疫反应性胞体。相对于其外边界，所有分区的中央部分含有明显较少的CART免疫反应性纤维，在这些外边界处CART纤维形成斑片状簇。总体而言，强烈的CART免疫反应性边界围绕着CART标记较弱的核心形成一个壳。双重免疫荧光标记显示CART与钙结合蛋白、钙视网膜蛋白或小白蛋白均不共定位，后三者的免疫反应性主要局限于胞体。钙视网膜蛋白的分布模式与钙结合蛋白的更相似，而与小白蛋白的不同。钙视网膜蛋白和钙结合蛋白在MGB的内侧和背侧分区表现出较高的免疫反应性，而小白蛋白在这些区域的染色较低。一般来说，尽管小白蛋白在所研究的所有Ca(2+)结合蛋白中免疫反应性最弱，但它在MGB的腹侧分区表达最高。我们的结果表明CART可能参与听觉，尽管其在内侧膝状体复合体中的免疫反应性不如在其他感觉脑区强烈。在豚鼠中，钙结合蛋白、钙视网膜蛋白和小白蛋白的异质性和互补模式很明显，然而，染色重叠似乎比在其他啮齿动物中更广泛。
