Postnatal changes in the Rexed lamination and markers of nociceptive afferents in the superficial dorsal horn of the rat
Postnatal changes in the Rexed lamination and markers of nociceptive afferents in the superficial dorsal horn of the rat
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DOI：
10.1002/cne.21691
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发表时间：
2008-06-01
影响因子：
2.5
通讯作者：
Ribeiro-Da-Silva, Alfredo
中科院分区：
文献类型：
--
作者：
Lorenzo, Louis-Etienne;Ramien, Michele;Ribeiro-Da-Silva, Alfredo
在本研究中，我们观察了出生后第0、5、10、15、20和60天大鼠腰髓背角Rexed‘s板层的变化和伤害性传入的分布。L4-L5节段横切面进行三重标记：异亮素B4(IB4)标记非肽能C纤维，降钙素基因相关肽(CGRP)免疫反应性标记伤害性多肽传入，尼氏荧光染色显示不同发育阶段的细胞和板层。尼氏染色显示，I板(LI)和外板II的厚度从出生到成年基本保持不变。CGRP传入纤维主要终止于LI和II板的外2/3处，而结合IB34的纤维终末区域集中在II板的中段1/3处。在绝对值上，强CGRP和IB4标记带的总宽度随年龄增加而增加，但占背角总厚度的百分比随着年龄的成熟而减少。CGRP终末区与IB4传入神经元的重叠区随着年龄的增长而增加。这些发现的后果是双重的。首先，不同椎板的大小并不是在背角上均匀生长。其次，CGRP和IB4标记本身不能被认为是发育过程中分层的可靠标记。这些发现对比较在未成熟组织和成熟组织中获得的关于背角结构的定位的数据有一定的意义。
In this study, we investigated postnatal changes in Rexed's laminae and distribution of nociceptive afferents in the dorsal horn of the rat lumbar spinal cord at postnatal days 0, 5, 10, 15, 20, and 60. Transverse sections of the L4-L5 segments were processed for triple labeling with isolectin B4 (IB4)-binding as a marker of nonpeptidergic C-fibers, calcitonin gene-related peptide (CGRP) immunoreactivity to label peptidergic nociceptive afferents, and a fluorescent Nissl stain to visualize cells and lamination at different stages of postnatal development. The Nissl staining revealed that the thickness of lamina I (LI) and outer lamina II remained mostly unchanged from birth until adulthood. CGRP afferents terminated mostly in LI and the outer two-thirds of lamina II, whereas the termination area of fibers binding IB34 was centered on the middle one-third of lamina II at all ages studied. In absolute values, the overall width of the bands of intense CGRP and IB4 labeling increased with age but decreased as a percentage of the overall thickness of the dorsal horn with maturation. The overlap of CGRP termination area with that of IB4 afferents increased with age. The consequences of these findings are twofold. First, the size of the different laminae does not grow evenly across the dorsal horn. Second, CGRP and IB4 labeling cannot be considered per se to be reliable markers of lamination during development. These findings have implications for comparing data obtained in immature and mature tissues with respect to localization of structures in the dorsal horn.