Takahashi Yuzuru, Chiba Tanemichi, Kurokawa Masahiro, Aoki Yasuchika
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Japan.
J Comp Neurol. 2003 Jul 14;462(1):29-41. doi: 10.1002/cne.10669.
Dermatomes and the associated central projection fields were studied with the application of fluorescent neurotracer, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), to 21 reference points on rat trunk and hindlimb skin. Segmental distribution and rostrocaudal central level of dorsal root ganglion (DRG) neurons innervating reference points were examined and DiI-induced fluorescent areas were mapped in the horizontal plane through lamina II of the dorsal horn. Segmental levels of DRG neurons innervating reference points were generally identical to the level determined using dye-extravasation methods. However, innervation of the first digit was situated in the L4 dermatome, not the L3 reported previously using those methods. Generally, afferents from a reference point projected to a single field in the ipsilateral dorsal horn. Reference points on ventral and dorsal median lines of the trunk were represented bilaterally. Afferents from reference points located on the ventral median line of the hindlimb projected to two separate fields: one on the medial margin of spinal cord segments L2-L5 and the other on the medial half of spinal cord segment L5. From the distribution of central projection fields of reference points, central projection fields of dermatomes were revealed as even in shape and located within corresponding spinal cord segments. The arrangement of peripheral and central fields of dermatomes and body surface regions suggests that peripheral and central projection fields of cutaneous afferent fibers are reshaped from the common prototypical pattern that exhibits an orderly and evenly sequenced arrangement.
通过将荧光神经示踪剂1,1'-二辛基-3,3,3',3'-四甲基吲哚羰花青高氯酸盐（DiI）应用于大鼠躯干和后肢皮肤的21个参考点，研究了皮节及其相关的中枢投射区域。检查了支配参考点的背根神经节（DRG）神经元的节段分布和 rostrocaudal 中枢水平，并在通过背角II层的水平面绘制了DiI诱导的荧光区域。支配参考点的DRG神经元的节段水平通常与使用染料外渗法确定的水平相同。然而，第一趾的神经支配位于L4皮节，而不是先前使用这些方法报告的L3。一般来说，来自参考点的传入纤维投射到同侧背角的单个区域。躯干腹侧和背侧中线的参考点双侧代表。来自后肢腹侧中线参考点的传入纤维投射到两个独立的区域：一个在脊髓节段L2-L5的内侧边缘，另一个在脊髓节段L5的内侧半。从参考点的中枢投射区域分布来看，皮节的中枢投射区域形状均匀，位于相应的脊髓节段内。皮节和体表区域的外周和中枢区域的排列表明，皮肤传入纤维的外周和中枢投射区域是从呈现有序和均匀序列排列的共同原型模式重塑而来的。
