Li Shuiyu, Yao Songping, Zhou Qiuying, Takahata Toru
Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China.
Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou, China.
Front Neuroanat. 2021 Oct 13;15:751810. doi: 10.3389/fnana.2021.751810. eCollection 2021.
Because at least some squirrel monkeys lack ocular dominance columns (ODCs) in the striate cortex (V1) that are detectable by cytochrome oxidase (CO) histochemistry, the functional importance of ODCs on stereoscopic 3-D vision has been questioned. However, conventional CO histochemistry or trans-synaptic tracer study has limited capacity to reveal cortical functional architecture, whereas the expression of immediate-early genes (IEGs), and , is more directly responsive to neuronal activity of cortical neurons to demonstrate ocular dominance (OD)-related domains in V1 following monocular inactivation. Thus, we wondered whether IEG expression would reveal ODCs in the squirrel monkey V1. In this study, we first examined CO histochemistry in V1 of five squirrel monkeys that were subjected to monocular enucleation or tetrodotoxin (TTX) treatment to address whether there is substantial cross-individual variation as reported previously. Then, we examined the IEG expression of the same V1 tissue to address whether OD-related domains are revealed. As a result, staining patterns of CO histochemistry were relatively homogeneous throughout layer 4 of V1. IEG expression was also moderate and homogeneous throughout layer 4 of V1 in all cases. On the other hand, the IEG expression was patchy in accordance with CO blobs outside layer 4, particularly in infragranular layers, although they may not directly represent OD clusters. Squirrel monkeys remain an exceptional species among anthropoid primates with regard to OD organization, and thus are potentially good subjects to study the development and function of ODCs.
由于至少一些松鼠猴的纹状皮层（V1）中缺乏可通过细胞色素氧化酶（CO）组织化学检测到的眼优势柱（ODC），因此ODC对立体三维视觉的功能重要性受到了质疑。然而，传统的CO组织化学或跨突触示踪研究揭示皮层功能结构的能力有限，而即刻早期基因（IEG）c-Fos和Zif268的表达对皮层神经元的神经元活动更直接地做出反应，以在单眼失活后显示V1中与眼优势（OD）相关的区域。因此，我们想知道IEG表达是否会揭示松鼠猴V1中的ODC。在本研究中，我们首先检查了五只接受单眼摘除或河豚毒素（TTX）处理的松鼠猴V1中的CO组织化学，以探讨是否存在如先前报道的个体间的显著差异。然后，我们检查了相同V1组织的IEG表达，以探讨是否能揭示与OD相关的区域。结果，CO组织化学的染色模式在V1的第4层中相对均匀。在所有情况下，IEG表达在V1的第4层中也适中且均匀。另一方面，IEG表达在第4层以外与CO斑片一致，呈斑片状，特别是在颗粒下层，尽管它们可能不直接代表OD簇。在OD组织方面，松鼠猴在类人猿灵长类动物中仍然是一个特殊的物种，因此可能是研究ODC发育和功能的良好对象。
