Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway
Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway
复制标题
DOI：
10.1523/jneurosci.3429-13.2013
复制
发表时间：
2013-11-06
影响因子：
5.3
通讯作者：
Luo, Wenqin
中科院分区：
文献类型：
--
作者：
Niu, Jingwen;Ding, Long;Luo, Wenqin
关于直接背柱（DDC）通路的功能组织的长期学说是“躯体位置图”模型，该模型表明躯体感觉传入主要由感受野而不是模态组织。使用模式特异性遗传追踪，在这里我们表明，上行机械感觉和本体感觉轴突（DDC传入的两种主要类型）在小鼠背柱和延髓中很大程度上分离为内侧-外侧模式。此外，我们发现这种基于模态的组织可能在包括人类在内的其他哺乳动物物种中是保守的。此外，我们确定了这两种类型的传入神经之间的关键形态差异，这解释了模态分离是如何形成的，以及为什么以前检测到一个粗略的“躯体位置图”。总的来说，我们的研究结果建立了一个新的哺乳动物直接背柱通路的功能组织模型，并提供了深入了解如何在中央躯体感觉通路的躯体位置和模态为基础的组织共存。
The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the "somatotopic map" model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial-lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough "somatotopic map" was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway.