Department of Veterinary Sciences, University of Pisa, Pisa, Italy.
Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy.
J Anat. 2021 Jan;238(1):1-12. doi: 10.1111/joa.13302. Epub 2020 Sep 3.
The present study analyses the organization and selected neurochemical features of the claustrum and visual cortex of the sheep, based on the patterns of calcium-binding proteins expression. Connections of the claustrum with the visual cortex have been studied by tractography. Parvalbumin-immunoreactive (PV-ir) and Calbindin-immunoreactive (CB-ir) cell bodies increased along the rostro-caudal axis of the nucleus. Calretinin (CR)-labeled somata were few and evenly distributed along the rostro-caudal axis. PV and CB distribution in the visual cortex was characterized by larger round and multipolar cells for PV, and more bitufted neurons for CB. The staining pattern for PV was the opposite of that of CR, which showed densely stained but rare cell bodies. Tractography shows the existence of connections with the caudal visual cortex. However, we detected no contralateral projection in the visuo-claustral interconnections. Since sheep and goats have laterally placed eyes and a limited binocular vision, the absence of contralateral projections could be of prime importance if confirmed by other studies, to rule out the role of the claustrum in stereopsis.
本研究基于钙结合蛋白表达模式分析了绵羊屏状核和视皮层的组织和选择神经化学特征。通过示踪研究了屏状核与视皮层的连接。钙结合蛋白免疫反应（PV-ir）和钙结合蛋白免疫反应（CB-ir）细胞体沿核的头尾轴增加。CR 标记的胞体数量较少，沿头尾轴均匀分布。视皮层中 PV 和 CB 的分布特征为 PV 为较大的圆形和多极细胞，CB 为更多的双足神经元。PV 的染色模式与 CR 相反，CR 显示染色浓密但细胞体稀少。示踪研究表明与尾侧视皮层存在连接。然而，在视-屏状核连接中，我们没有检测到对侧投射。由于绵羊和山羊的眼睛位于侧面，双眼视觉有限，如果其他研究证实，对侧投射的缺失可能非常重要，以排除屏状核对立体视觉的作用。
