声刺激在行为猴中既激活了半规管又激活了耳石前庭眼动反射通路。
Acoustic clicks activate both the canal and otolith vestibulo-ocular reflex pathways in behaving monkeys.
机构信息
Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
出版信息
J Assoc Res Otolaryngol. 2009 Dec;10(4):569-77. doi: 10.1007/s10162-009-0178-7. Epub 2009 Jul 21.
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.
前庭系统的声学激活在人类和动物模型中已有充分的记录。在过去的十年中,胸锁乳突肌(cVEMP)和眼外肌(oVEMP)中的声诱发肌源性电位已被广泛研究,并且它们作为新的前庭功能测试的潜力已得到广泛认可。然而,声音激活耳石和管途径的程度仍存在争议。在本研究中,我们在最近开发的非人类灵长类动物前庭系统声学激活模型中研究了这个问题,即在行为猴子中进行的声诱发前庭眼反射(VOR)。为了确定管和耳石 VOR 途径是否被声音激活,我们分析了外展神经神经元对分别送入每个耳朵的咔嗒声的反应。主要发现是,咔嗒声诱发出现在两侧的外展神经神经元的短潜伏期兴奋性反应。然而,这两个反应的潜伏期不同。对侧和同侧外展神经神经元的平均潜伏期分别为 2.44 +/- 0.4 和 1.65 +/- 0.28 毫秒。对兴奋性潜伏期的进一步分析,结合已知的管和耳石 VOR 途径,表明对侧外展神经神经元的兴奋性反应是由连接侧管和对侧外展神经神经元的对侧双突触 VOR 途径介导的,而同侧外展神经神经元的兴奋性反应是由连接耳石和同侧外展神经神经元的同侧单突触 VOR 途径介导的。这些结果为理解声诱发前庭反应的神经基础提供了新的见解,这对于开发人类管和耳石功能的新测试至关重要。