The response of guinea pig primary utricular and saccular irregular neurons to bone-conducted vibration (BCV) and air-conducted, sound (ACS)
The response of guinea pig primary utricular and saccular irregular neurons to bone-conducted vibration (BCV) and air-conducted, sound (ACS)
复制标题
DOI：
10.1016/j.heares.2015.10.019
复制
发表时间：
2016-01-01
期刊：
影响因子：
2.8
通讯作者：
Goonetilleke, Samanthi C.
中科院分区：
文献类型：
--
作者：
Curthoys, Ian S.;Vulovic, Vedran;Goonetilleke, Samanthi C.
本研究旨在通过测量豚鼠单个初级椭圆囊和囊状传入神经元的静息放电率、放电率增加阈值和阈上敏感性函数来表征哺乳动物初级耳石神经元对声音和振动的反应。不规则静息放电的神经元被激活，以响应骨传导振动（BCV）和空气传导声音（ACS）的频率在100 Hz和3000 Hz之间。神经元的位置进行了验证标记neurobiotin.Many传入从两个maculae有非常低或零静息放电，囊状传入平均，较高的静息速率比椭圆囊传入。大多数不规则的椭圆囊和囊状传入可以由BCV和ACS诱发。对于BCV刺激：椭圆囊和囊状神经元对于从100 Hz到750 Hz的频率的增加的放电速率（平均约0.02 g）显示出类似的低阈值。对于高于750 Hz的BCV频率，速率更改阈值会急剧增加。对于椭圆囊和囊状神经元，BCV的阈上灵敏度函数是相似的，在低频下，随着强度的增加，放电率非常陡峭地增加。对于ACS刺激：椭圆囊和囊状神经元可以被频率为250 Hz至3000 Hz的高强度刺激激活，具有类似的平坦U形调谐曲线，其中频率约为1000 Hz时具有最低阈值。2000赫兹。在这些频率上，囊状传入神经的平均ACS阈值比椭圆囊神经元低约15-20 dB。对于ACS，椭圆囊和囊状神经元的阈上敏感性函数是相似的。椭圆囊和囊状神经元的传入对BCV和ACS都表现出锁相，延伸到至少约1500 Hz的频率（对于BCV）和3000 Hz的频率（对于ACS）。低频锁相（例如，100 Hz）对由刺激诱发的神经放电速率施加限制，因为神经元通常在刺激的每个周期发射一个尖峰。这些结果与Young等人（1977）提出的假设雅阁，即波形的每个单独的周期，无论是BCV还是ACS，是对任一黄斑上的受体毛细胞的有效刺激。我们认为，每个周期的BCV或ACS刺激引起流体位移偏转的短，硬，毛束的I型受体在纹状体，因此触发了锁相的初级耳石传入神经反应。皇冠版权所有（C）2015由Elsevier B. V.出版。保留所有权利。
This study sought to characterize the response of mammalian primary otolithic neurons to sound and vibration by measuring the resting discharge rates, thresholds for increases in firing rate and supra threshold sensitivity functions of guinea pig single primary utricular and saccular afferents. Neurons with irregular resting discharge were activated in response to bone conducted vibration (BCV) and air conducted sound (ACS) for frequencies between 100 Hz and 3000 Hz. The location of neurons was verified by labelling with neurobiotin.Many afferents from both maculae have very low or zero resting discharge, with saccular afferents having on average, higher resting rates than utricular afferents. Most irregular utricular and saccular afferents can be evoked by both BCV and ACS. For BCV stimulation: utricular and saccular neurons show similar low thresholds for increased firing rate (around 0.02 g on average) for frequencies from 100 Hz to 750 Hz. There is a steep increase in rate change threshold for BCV frequencies above 750 Hz. The suprathreshold sensitivity functions for BCV were similar for both utricular and saccular neurons, with, at low frequencies, very steep increases in firing rate as intensity increased.For ACS stimulation: utricular and saccular neurons can be activated by high intensity stimuli for frequencies from 250 Hz to 3000 Hz with similar flattened U-shaped tuning curves with lowest thresholds for frequencies around 1000-2000 Hz. The average ACS thresholds for saccular afferents across these frequencies is about 15-20 dB lower than for utricular neurons. The suprathreshold sensitivity functions for ACS were similar for both utricular and saccular neurons.Both utricular and saccular afferents showed phase-locking to BCV and ACS, extending up to frequencies of at least around 1500 Hz for BCV and 3000 Hz for ACS. Phase-locking at low frequencies (e.g. 100 Hz) imposes a limit on the neural firing rate evoked by the stimulus since the neurons usually fire one spike per cycle of the stimulus.Conclusion: These results are in accord with the hypothesis put forward by Young et al. (1977) that each individual cycle of the waveform, either BCV or ACS, is the effective stimulus to the receptor hair cells on either macula. We suggest that each cycle of the BCV or ACS stimulus causes fluid displacement which deflects the short, stiff, hair bundles of type I receptors at the striola and so triggers the phase-locked neural response of primary otolithic afferents. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.