Lee Jea-Young, Jeong Se-Jin, Jeon Chang-Jin
Department of Biology, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University, Daegu 702-701, South Korea.
Zoolog Sci. 2014 Nov;31(11):748-57. doi: 10.2108/zs140073.
Parvalbumin (PV) is thought to play a major role in buffering intracellular calcium. We studied the distribution, morphology of PV-immunoreactive (IR) cells, and the effect of enucleation on the PV distribution in the superior colliculus (SC) in dog (Canis familiaris) and compared PV labeling to that of calbindin D28K (CB) and GABA. These cells formed three laminar tiers in the dog SC; 1) the upper superficial gray layer (SGL), 2) the lower optic layer (OL) and the upper intermediate gray layer, and 3) the deep layer. The third tier was not very distinct when compared with the other two tiers. The distribution of PV-IR cells is thus complementary to that of CB-IR tiers. Our present data on the distribution of PV-IR cells within the superficial layers are strikingly different from those in previously studied mammals, which show PV-IR cells within the lower SGL and upper OL. However, there were no distinct differences in distribution within the deep layers compared with that of previously studied mammals. PV-IR cells in the SC varied dramatically in morphology and size, and included round/oval, vertical fusiform, stellate, horizontal and pyriform cells. Two-color immunofluorescence revealed quantitatively that 11.67% of the PV-IR cells colocalized with GABA. Monocular enucleation appeared to have no effect on the distribution of PV-IR cells in the contralateral SC. Similar to CB, these data suggest that retinal projection may not control the expression of PV in the dog SC. These results provide important information for delineating similarities and differences in the neurochemical architecture of the visual system.
小白蛋白（PV）被认为在缓冲细胞内钙方面起主要作用。我们研究了犬（家犬）上丘（SC）中PV免疫反应性（IR）细胞的分布、形态以及去核对上丘PV分布的影响，并将PV标记与钙结合蛋白D28K（CB）和γ-氨基丁酸（GABA）的标记进行了比较。这些细胞在犬上丘形成了三个分层；1）上部浅灰质层（SGL），2）下部视层（OL）和上部中间灰质层，以及3）深层。与其他两层相比，第三层不是很明显。因此，PV-IR细胞的分布与CB-IR层的分布互补。我们目前关于浅层内PV-IR细胞分布的数据与先前研究的哺乳动物有显著不同，先前研究的哺乳动物显示PV-IR细胞位于下部SGL和上部OL内。然而，与先前研究的哺乳动物相比，深层内的分布没有明显差异。上丘中的PV-IR细胞在形态和大小上差异很大，包括圆形/椭圆形、垂直梭形、星形、水平形和梨形细胞。双色免疫荧光定量显示，11.67%的PV-IR细胞与GABA共定位。单眼摘除似乎对上丘对侧PV-IR细胞的分布没有影响。与CB相似，这些数据表明视网膜投射可能不控制犬上丘中PV的表达。这些结果为描绘视觉系统神经化学结构的异同提供了重要信息。
