Department of Anatomy and Neurobiology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan.
Division of Anatomy and Embryology, Department of Functional Biomedicine, Ehime University, Toon, Japan.
Front Neural Circuits. 2022 Jul 4;16:863478. doi: 10.3389/fncir.2022.863478. eCollection 2022.
The marmoset (a New World monkey) has recently received much attention as an experimental animal model; however, little is known about the connectivity of limbic regions, including cortical and hippocampal memory circuits, in the marmoset. Here, we investigated the neuronal connectivity of the marmoset, especially focusing on the connectivity between the hippocampal formation and the presubiculum, using retrograde and anterograde tracers (cholera toxin-B subunit and biotin dextran amine). We demonstrated the presence of a direct projection from the CA1 pyramidal cell layer to the deep layers of the presubiculum in the marmoset, which was previously identified in the rabbit brain, but not in the rat. We also found that the cells of origin of the subiculo-presubicular projections were localized in the middle part along the superficial-to-deep axis of the pyramidal cell layer of the distal subiculum in the marmoset, which was similar to that in both rats and rabbits. Our results suggest that, compared to the rat and rabbit brains, connections between the hippocampal formation and presubiculum are highly organized and characteristic in the marmoset brain.
狨猴（新世界猴）最近作为一种实验动物模型受到了广泛关注；然而，对于其边缘区域（包括皮质和海马记忆回路）的连接性知之甚少。在这里，我们使用逆行和顺行示踪剂（霍乱毒素 B 亚单位和生物素葡聚糖胺）研究了狨猴的神经元连接性，特别是海马结构与前下托之间的连接性。我们证明了在狨猴中存在从 CA1 锥体细胞层到前下托深部的直接投射，这在前兔脑中已被证实，但在大鼠中没有。我们还发现，亚基 - 前下托投射的起始细胞位于狨猴远端亚基的沿浅层到深层的锥体细胞层的中部分，这与大鼠和兔相似。我们的结果表明，与大鼠和兔脑相比，狨猴脑中海马结构和前下托之间的连接高度组织化且具有特征性。
