Characterization of pruriceptive trigeminothalamic tract neurons in rats
Characterization of pruriceptive trigeminothalamic tract neurons in rats
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DOI：
10.1152/jn.00668.2013
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发表时间：
2014-04-01
影响因子：
2.5
通讯作者：
Giesler, Glenn J., Jr.
中科院分区：
文献类型：
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作者：
Moser, Hannah R.;Giesler, Glenn J., Jr.
啮齿类动物的面部瘙痒和疼痛模型为区分与每种感觉相关的行为提供了有价值的工具。在大鼠中，将致敏原应用于面部引起使用后肢的抓挠，而致敏原引起使用前肢的擦拭。我们希望确定三叉丘脑束（VTT）神经元在将面部瘙痒和疼痛信息传递到前脑中的作用。我们的特点是面部应用的致敏剂（5-羟色胺，BAM 8 -22，氯喹，组胺，辣椒素，和cowhage）和104 VTT神经元记录麻醉大鼠的伤害性刺激的反应。每个VTT神经元有一个机械敏感的皮肤感受野同侧的脸。所有的伤害性VTT神经元也对有害的机械和/或热刺激作出反应。超过一半的VTT神经元对伤害性刺激有反应，也对至少一种促肾上腺皮质激素有反应。每一个测试的促肾上腺皮质激素，除牛，产生了一个子集的VTT神经元的放电率增加。对每种促凝血酶原的反应进行了表征，包括最大放电速率、反应持续时间和尖峰时间动态。Pruriceptive VTT神经元记录从整个三叉神经脊束核的浅层和深层，并显示通过逆向映射到腹后内侧核或丘脑后核的项目。这些结果表明，vacciceptive VTT神经元是一个子集的多模态伤害性VTT神经元和表征系统有利于未来的实验，面部瘙痒和疼痛之间的相似性和差异。
Rodent models of facial itch and pain provide a valuable tool for distinguishing between behaviors related to each sensation. In rats, pruritogens applied to the face elicit scratching using the hindlimb while algogens elicit wiping using the forelimb. We wished to determine the role of trigeminothalamic tract (VTT) neurons in carrying information regarding facial itch and pain to the forebrain. We have characterized responses to facially applied pruritogens (serotonin, BAM8-22, chloroquine, histamine, capsaicin, and cowhage) and noxious stimuli in 104 VTT neurons recorded from anesthetized rats. Each VTT neuron had a mechanically sensitive cutaneous receptive field on the ipsilateral face. All pruriceptive VTT neurons also responded to noxious mechanical and/or thermal stimulation. Over half of VTT neurons responsive to noxious stimuli also responded to at least one pruritogen. Each tested pruritogen, with the exception of cowhage, produced an increase in discharge rate in a subset of VTT neurons. The response to each pruritogen was characterized, including maximum discharge rate, response duration, and spike timing dynamics. Pruriceptive VTT neurons were recorded from throughout superficial and deep layers of the spinal trigeminal nucleus and were shown to project via antidromic mapping to the ventroposterior medial nucleus or posterior thalamic nuclei. These results indicate that pruriceptive VTT neurons are a subset of polymodal nociceptive VTT neurons and characterize a system conducive to future experiments regarding the similarities and differences between facial itch and pain.