Critical evaluation of the colocalization between calcitonin gene-related peptide, substance P, transient receptor potential vanilloid subfamily type 1 immunoreactivities, and isolectin B4 binding in primary afferent neurons of the rat and mouse
Critical evaluation of the colocalization between calcitonin gene-related peptide, substance P, transient receptor potential vanilloid subfamily type 1 immunoreactivities, and isolectin B4 binding in primary afferent neurons of the rat and mouse
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DOI：
10.1016/j.jpain.2006.09.005
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发表时间：
2007-03-01
期刊：
影响因子：
4
通讯作者：
Flores, Christopher M.
中科院分区：
文献类型：
--
作者：
Price, Theodore J.;Flores, Christopher M.
降钙素基因相关肽(CGRP)和/或P物质(SP)免疫反应以及异凝素B-4(IB4)结合分别被用来定义肽能和非肽能伤害性感受器群体。尽管这一界限在小鼠身上得到了很好的支持，但越来越多的证据表明，在大鼠身上并非如此。因此，本研究对神经肽CGRP和SP与IB4结合部位和瞬时受体电位香草亚家族1型(TRPV1)通道在成年大鼠三叉神经节(TG)和背根节(DRG)中的共存进行了评价和定量研究。这些结果表明，在大鼠感觉神经节中，肽能神经元(即表达CGRP和SP的神经元)和结合IB4的神经元之间有很大的重叠(类似于DRG中的45%和TG中的30%)。然而，这些标记物在背根节和TG之间的共定位也有显著差异。例如，在背根节，表达IB4结合部位的CGRP免疫反应阳性神经元(44.5%)明显多于TG(27.5%)。相反，背根神经节内共定位TRPV1的CGRP免疫反应神经元(49.2%)明显少于TG(70%)。此外，我们使用在大鼠和小鼠的TG中识别CGRP和IB4的CGRP抗体直接评估了CGRP和IB4在这两个物种中的共存。因此，虽然在小鼠的TG神经元中只观察到大约10%的重叠，但在大鼠的TG神经元中观察到显著的重叠(类似于35%)。观点：这些数据表明，在成年大鼠的感觉神经节中，作为IB4结合的函数，肽能和非肽能伤害性感受器亚类之间没有明显的区别。此外，TG和DRG在一起共同表达常用的伤害性神经元标记物的程度上存在显著差异，本研究结果要求在推断关于感觉神经节或物种之间(包括人类)神经元的神经化学分类的实验结论时要谨慎。(C)2007年，由美国疼痛协会提供。
Calcitonin gene-related peptide (CGRP) and/or substance P (SP) immunoreactivity as well as isolectin B-4 (IB4) binding are commonly used to define peptidergic and non-peptidergic nociceptor populations, respectively. Although this demarcation is well supported in the mouse, there is accumulating evidence to suggest it is not so in the rat. Hence, this investigation was undertaken to evaluate and quantify the colocalization of the neuropeptides CGRP and SP with IB4 binding sites and the transient receptor potential vanilloid subfamily type 1 (TRPV1) channel and to compare this colocalization between trigeminal (TG) and dorsal root ganglia (DRG) in adult rats. These findings illustrate that there is a substantial overlap (similar to 45% in the DRG and similar to 30% in the TG) between peptidergic neurons (ie, CGRP- and SP-expressing) and neurons that bind IB4 in rat sensory ganglia. However, there were also significant differences in the colocalization of these markers between the DRG and TG. For instance, in the DRG, significantly more CGRP-immunoreactive neurons also expressed IB4 binding sites (44.5%) compared with the TG (27.5%). In contrast, significantly fewer CGRP-immunoreactive neurons in the DRG colocalized TRPV1 immunoreactivity (49.2%) compared with the TG (70%). Moreover, we directly assessed the colocalization of CGRP and IB4 in the TG of rats and mice using a CGRP antibody that recognizes this peptide in both species. Thus, whereas only an approximately 10% overlap was observed in TG neurons of mouse, significantly greater overlap (similar to 35%) was observed in those of rat.Perspective: These data indicate that in adult rat sensory ganglia, there is not a clear distinction between the peptidergic and non-peptidergic nociceptor subclasses as a function of IB4 binding. Furthermore, there are significant differences between the TG and DRG in the degree to which commonly utilized nociceptive neuronal markers are co-expressed Taken together, the present findings dictate prudence when extrapolating experimental conclusions about the neurochemical classification of neurons between sensory ganglia or between species, including humans. (C) 2007 by the American Pain Society.