Intense noise exposure alters peripheral vestibular structures and physiology
Intense noise exposure alters peripheral vestibular structures and physiology
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DOI：
10.1152/jn.00642.2019
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发表时间：
2020-02-01
影响因子：
2.5
通讯作者：
King, W. M.
中科院分区：
文献类型：
--
作者：
Stewart, C. E.;Bauer, D. S.;King, W. M.
耳石器官在检测线加速度和重力以控制姿势和平衡方面起着至关重要的作用。一些支配这些结构的传入可以被声音激活，并面临噪音过度刺激的风险。以前的报道表明，噪声暴露可以取消前庭短潜伏期诱发电位(VsEP)反应，并损害肾盏终末。然而，用于引发反应的刺激比先前研究中确定的刺激要弱，可能不足以在噪声暴露的动物中引发VsEP反应。本研究的目的是确定已建立的噪声暴露范式对使用大头抽动刺激的VsEP反应的影响，以确定噪声是否诱导刺激阈值移动和/或大抽头刺激是否能够在噪声暴露的大鼠中诱发VsEP反应。另一个目标是将这些测量与噪声暴露组织与非噪声暴露组织中存在的肾盏终末和毛细胞的数量相关联。暴露在强烈的连续噪声中，VsEP对大刺激的反应显著降低，而对小刺激的VsEP反应消失。这一发现证实，虽然可测量的VsEP反应可以从噪声损伤的大鼠球囊中引发，但需要更大的头部抽动刺激，这表明唤起VsEP所需的最小刺激发生了变化。另外。观察到仅标记的花萼传入终末减少，但没有伴随着花萼或毛细胞总数的减少。这一发现支持了在VsEP反应的产生中表达Calretinin的仅有花盏的传入神经元的关键作用。新的和值得注意的是，这项研究发现在噪声诱导的前庭周围损伤后，诱发前庭短潜伏期诱发电位(VsEP)反应所需的最小刺激发生了变化，球囊纹状体区域仅有Calretinin标记的仅有Calyx的传入终末的数量减少。这些数据表明，单一强烈的噪声暴露可能会影响球囊纹状体区域仅有花瓣的终末的突触功能。Calretinin免疫标记的减少可能有助于深入了解噪声诱导的VsEP反应变化的潜在机制。
The otolith organs play a critical role in detecting linear acceleration and gravity to control posture and balance. Some afferents that innervate these structures can be activated by sound and are at risk for noise over-stimulation. A previous report demonstrated that noise exposure can abolish vestibular short-latency evoked potential (VsEP) responses and damage calyceal terminals. However, the stimuli that were used to elicit responses were weaker than those established in previous studies and may have been insufficient to elicit VsEP responses in noise-exposed animals. The goal of this study was to determine the effect of an established noise exposure paradigm on VsEP responses using large head-jerk stimuli to determine if noise induces a stimulus threshold shift and/or if large head-jerks are capable of evoking VsEP responses in noise-exposed rats. An additional goal is to relate these measurements to the number of calyceal terminals and hair cells present in noise-exposed vs. non-noise-exposed tissue. Exposure to intense continuous noise significantly reduced VsEP responses to large stimuli and abolished VsEP responses to small stimuli. This finding confirms that while measurable VsEP responses can be elicited from noise-lesioned rat sacculi, larger head-jerk stimuli are required, suggesting a shift in the minimum stimulus necessary to evoke the VsEP. Additionally. a reduction in labeled calyx-only afferent terminals was observed without a concomitant reduction in the overall number of calyces or hair cells. This finding supports a critical role of calretinin-expressing calyceal-only afferents in the generation of a VsEP response.NEW & NOTEWORTHY This study identifies a change in the minimum stimulus necessary to evoke vestibular short-latency evoked potential (VsEP) responses after noise-induced damage to the vestibular periphery and reduced numbers of calretinin-labeled calyx-only afferent terminals in the striolar region of the sacculus. These data suggest that a single intense noise exposure may impact synaptic function in calyx-only terminals in the striolar region of the sacculus. Reduced calretinin immunolabeling may provide insight into the mechanism underlying noise-induced changes in VsEP responses.