Expression of vanilloid receptor TRPV1 in the rat trigentinal sensory nuclei
Expression of vanilloid receptor TRPV1 in the rat trigentinal sensory nuclei
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DOI：
10.1002/cne.20272
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发表时间：
2004-10-04
影响因子：
2.5
通讯作者：
Valtschanoff, JG
中科院分区：
文献类型：
--
作者：
Bae, YC;Oh, JM;Valtschanoff, JG
对于表达香草样蛋白受体TRPV1的三叉神经传入神经元的中枢投射模式及其神经调节肽的共表达知之甚少。为了解决这些问题，我们通过光镜和电镜检查了trpv1阳性神经元在大鼠三叉神经节（TG）和三叉感觉主核（Vp）、口核（Vo）、内突核（Vi）和尾核（Vc）中的分布。此外，我们通过共聚焦显微镜研究了trpv1阳性神经元与P物质（SP）和降钙素基因相关肽（CGRP）的共定位。在TG中，只有中小神经元TRPV1免疫阳性。TRPV1在Vp、Vo和Vi背侧的轴突侧枝以及Vc的I层和II层外区（IIo）的末端和纤维中均有染色。电镜下发现三叉神经升、降束trpv1阳性纤维无髓鞘。Vc中几乎所有trpv1阳性末端都含有大量大的密核囊泡，并与单个小树突形成突触接触。多重免疫荧光显示TRPV1与SP和CGRP高度共定位于TG神经元以及Vc的I和IIo层的纤维和终末。这些结果表明，无髓鞘(C)传入神经对辣味和辣椒素敏感的中枢投射在Vc和三叉神经吻侧核之间的组织不同，Vc可能在痛觉过敏的发生中起作用。(C) 2004 Wiley-Liss, Inc。
Little is known about the central projection patterns of trigeminal afferent neurons expressing the vanilloid receptor TRPV1 and their coexpression of neuromodulatory peptides. To address these issues, we examined the distribution of TRPV1-positive neurons in the trigeminal ganglion (TG) and trigeminal sensory nuclei principalis (Vp), oralis (Vo), interpolaris (Vi), and caudalis (Vc) in the rat via light and electron microscopy. In addition, we studied the colocalization of TRPV1-positive neurons with substance P (SP) and calcitonin gene-related peptide (CGRP) via confocal microscopy. In TG, only small and medium-sized neurons were immunopositive for TRPV1. The staining for TRPV1 was found in axon collaterals in the dorsal parts of Vp, Vo, and Vi and in terminals and fibers throughout lamina I and the outer zone of lamina II (IIo) of Vc. With electron microscopy, TRPV1-positive fibers in the ascending and descending trigeminal tracts were found to be unmyelinated. Almost all TRPV1-positive terminals in Vc contained numerous large dense-core vesicles and formed synaptic contacts with single small dendrites. Multiple immunofluorescence revealed a high degree of colocalization of TRPV1 with SP and CGRP in TG neurons as well as in fibers and terminals confined to laminae I and IIo of Vc. These results suggest that the central projections of unmyelinated (C) afferents sensitive to noxious heat and capsaicin are organized differently between Vc and the rostral trigeminal nuclei and that Vc may play a role in the development of hyperalgesia. (C) 2004 Wiley-Liss, Inc.