Zhang Huimin, Wang Xiaojun, Guo Wenyan, Li Anan, Chen Ruixi, Huang Fei, Liu Xiaoxiang, Chen Yijun, Li Ning, Liu Xiuli, Xu Tonghui, Xue Zheng, Zeng Shaoqun
Collaborative Innovation Center for Biomedical Engineering, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, China.
Britton Chance Center and MOE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.
Front Neuroanat. 2021 Oct 28;15:724861. doi: 10.3389/fnana.2021.724861. eCollection 2021.
Whisker detection is crucial to adapt to the environment for some animals, but how the nervous system processes and integrates whisker information is still an open question. It is well-known that two main parallel pathways through Ventral posteromedial thalamic nucleus (VPM) ascend to the barrel cortex, and classical theory suggests that the cross-talk from trigeminal nucleus interpolaris (Sp5i) to principal nucleus (Pr5) between the main parallel pathways contributes to the multi-whisker integration in barrel columns. Moreover, some studies suggest there are other cross-streams between the parallel pathways. To confirm their existence, in this study we used a dual-viral labeling strategy and high-resolution, large-volume light imaging to get the complete morphology of individual VPM neurons and trace their projections. We found some new thalamocortical projections from the ventral lateral part of VPM (VPMvl) to barrel columns. In addition, the retrograde-viral labeling and imaging results showed there were the large trigeminothalamic projections from Sp5i to the dorsomedial section of VPM (VPMdm). Our results reveal new cross-streams between the parallel pathways through VPM, which may involve the execution of multi-whisker integration in barrel columns.
对一些动物来说，触须检测对于适应环境至关重要，但神经系统如何处理和整合触须信息仍是一个悬而未决的问题。众所周知，有两条主要的平行通路通过腹后内侧丘脑核（VPM）通向桶状皮层，经典理论认为，在主要平行通路之间，从三叉神经极间核（Sp5i）到主核（Pr5）的串扰有助于桶状柱中的多触须整合。此外，一些研究表明，平行通路之间还存在其他交叉信息流。为了证实它们的存在，在本研究中，我们使用了双病毒标记策略和高分辨率、大体积光成像技术，以获取单个VPM神经元的完整形态并追踪其投射。我们发现了一些从VPM腹外侧部分（VPMvl）到桶状柱的新的丘脑皮质投射。此外，逆行病毒标记和成像结果显示，存在从Sp5i到VPM背内侧部分（VPMdm）的大量三叉丘脑投射。我们的结果揭示了通过VPM的平行通路之间新的交叉信息流，这可能涉及桶状柱中多触须整合的执行。
