Acoustic Clicks Activate both the Canal and Otolith Vestibulo-Ocular Reflex Pathways in Behaving Monkeys
Acoustic Clicks Activate both the Canal and Otolith Vestibulo-Ocular Reflex Pathways in Behaving Monkeys
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DOI：
10.1007/s10162-009-0178-7
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发表时间：
2009-12-01
影响因子：
2.4
通讯作者：
Zhou, Wu
中科院分区：
文献类型：
--
作者：
Xu, Youguo;Simpson, Ivra;Zhou, Wu
前庭系统的声学激活在人类和动物模型中已有很好的记录。近十年来，声诱发的胸锁乳突肌肌源性电位（cVEMP）和眼外肌肌源性电位（oVEMP）得到了广泛的研究，其作为前庭功能检测的新方法得到了广泛的认可。然而，声音激活耳石和耳道通路的程度仍然存在争议。在本研究中，我们在最近开发的前庭系统声学激活的非人灵长类动物模型中研究了这个问题，即，声音诱发的前庭眼反射（VOR）在行为猴子。为了确定耳道和耳石VOR通路是否被声音激活，我们分析了外展神经元对传递到任何一只耳朵的点击的反应。主要发现是短声诱发两侧外展神经元的短潜伏期兴奋性反应。然而，这两种反应的延迟是不同的。对侧和同侧外展神经元的平均潜伏期分别为2.44 +/- 0.4和1.65 +/- 0.28 ms。结合已知的神经管和耳石VOR通路，对兴奋性延髓的进一步分析表明，对侧外展神经元的兴奋性反应是由连接侧神经管和对侧外展神经元的对侧双突触VOR通路介导的，同侧外展神经元的兴奋性反应是由同侧连接椭圆囊和外展神经的单突触VOR通路介导的。同侧外展神经元这些结果提供了新的见解，了解声音诱发前庭反应的神经基础，这是必不可少的开发新的测试在人类的运河和耳石功能。
Acoustic activation of the vestibular system has been well documented in humans and animal models. In the past decade, sound-evoked myogenic potentials in the sternocleidomastoid muscle (cVEMP) and the extraocular muscles (oVEMP) have been extensively studied, and their potentials as new tests for vestibular function have been widely recognized. However, the extent to which sound activates the otolith and canal pathways remains controversial. In the present study, we examined this issue in a recently developed nonhuman primate model of acoustic activation of the vestibular system, i.e., sound-evoked vestibulo-ocular reflexes (VOR) in behaving monkeys. To determine whether the canal and otolith VOR pathways are activated by sound, we analyzed abducens neurons' responses to clicks that were delivered into either ear. The main finding was that clicks evoked short-latency excitatory responses in abducens neurons on both sides. The latencies of the two responses, however, were different. The mean latency of the contralateral and ipsilateral abducens neurons was 2.44 +/- 0.4 and 1.65 +/- 0.28 ms, respectively. A further analysis of the excitatory latencies, in combination with the known canal and otolith VOR pathways, suggests that the excitatory responses of the contralateral abducens neurons were mediated by the contralateral disynaptic VOR pathways that connect the lateral canal to the contralateral abducens neurons, and the excitatory responses of the ipsilateral abducens neurons were mediated by the ipsilateral monosynaptic VOR pathways that connect the utricle to the ipsilateral abducens neurons. These results provide new insights into the understanding of the neural basis for sound-evoked vestibular responses, which is essential for developing new tests for both canal and otolith functions in humans.