Organization of intralaminar and translaminar neuronal connectivity in the superficial spinal dorsal horn.
Organization of intralaminar and translaminar neuronal connectivity in the superficial spinal dorsal horn.
复制标题
DOI：
10.1523/jneurosci.6175-08.2009
复制
发表时间：
2009-04-22
期刊：
影响因子：
--
通讯作者：
Strassman AM
中科院分区：
文献类型：
--
作者：
Kato G;Kawasaki Y;Koga K;Uta D;Kosugi M;Yasaka T;Yoshimura M;Ji RR;Strassman AM
脊髓背角表现出高度的内在连通性，这对其在处理伤害性信息中的作用至关重要。为了研究这种内在联系的空间组织结构，我们在腰椎脊髓矢状面和横切面采用激光扫描光刺激技术，通过谷氨酸去掉刺激突触前神经元，并定位了向浅层神经元提供兴奋性和抑制性突触输入的位置。板层II内的兴奋性神经元间连接显示出明显的矢状方向，这与初级传入投射模式中存在的躯体组织相一致。所有类型的II板层神经元的兴奋性输入来自比抑制性输入更宽的吻尾区，而兴奋性和抑制性输入区都受到内侧的限制。板层I-II神经元在兴奋性输入的板层分布中表现出细胞类型的特异性模式，这与其背腹侧树突的扩张有关。所有类型的细胞主要接受来自其胞体腹侧的兴奋性输入，但在板层I神经元和板层II垂直细胞中，兴奋性输入区的腹侧移位大于其他类型的细胞，导致更明显的跨层输入模式。在垂直细胞群的一个子集中，发现了一种以前未知的从III-IV板层到浅层背角的兴奋性输入。这些结果揭示了兴奋性和抑制性连接的局部模式中的一种特殊的三维组织，这对与躯体复制和感觉通道相关的信息处理具有意义。
The spinal dorsal horn exhibits a high degree of intrinsic connectivity that is critical to its role in the processing of nociceptive information. To examine the spatial organization of this intrinsic connectivity, we used laser scanning photostimulation in parasagittal and transverse slices of lumbar spinal cord to stimulate presynaptic neurons by glutamate uncaging, and mapped the location of sites that provide excitatory and inhibitory synaptic input to neurons of the superficial laminae. Excitatory interneuronal connectivity within lamina II exhibited a pronounced sagittal orientation, in keeping with the somatotopic organization present in the pattern of primary afferent projections. Excitatory inputs to all classes of lamina II neurons arose from a wider rostrocaudal area than inhibitory inputs, while both excitatory and inhibitory input zones were restricted mediolaterally. Lamina I-II neurons exhibited cell-type-specific patterns in the laminar distribution of their excitatory inputs that were related to their dorsoventral dendritic expanse. All cell types received excitatory input predominantly from positions ventral to that of their soma, but in lamina I neurons and lamina II vertical cells this ventral displacement of the excitatory input zone was greater than in the other cell types, resulting in a more pronounced translaminar input pattern. A previously unknown excitatory input to the superficial dorsal horn from lamina III-IV was identified in a subset of the vertical cell population. These results reveal a specific three-dimensional organization in the local patterns of excitatory and inhibitory connectivity that has implications for the processing of information related to both somatotopy and sensory modality.