The Meniere's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, 2050, Australia.
Vestibular Research Laboratory, The University of Sydney, School of Psychology, Sydney, NSW, 2050, Australia.
Hear Res. 2018 Dec;370:232-237. doi: 10.1016/j.heares.2018.08.005. Epub 2018 Aug 24.
With the use of a commercially available Laser Doppler Vibrometer (LDV) we have measured the velocity of the surgically exposed utricular macula in the dorsoventral plane, in anaesthetized guinea pigs, during Air Conducted Sound (ACS) or Bone Conducted Vibration (BCV) stimulation. We have also performed simultaneous measurements of otolithic function in the form of the Utricular Microphonic (UM) and the Vestibular short-latency Evoked Potential (VsEP). Based on the level of macular vibration measured with the LDV, the UM was most sensitive to ACS and BCV between 100 and 200 Hz. The phase of the UM relative to the phase of the macular motion was relatively consistent across frequency for ACS stimulation, but varied by several cycles for BCV stimulation, suggesting a different macromechanical mode of utricular receptor activation. Moreover, unlike ACS, BCV evoked substantially distorted UM and macular vibration responses at certain frequencies, most likely due to complex resonances of the skull. Analogous to LDV studies of organ of Corti vibration, this method provides the means to study the dynamic response of the utricular macula whilst simultaneously measuring function.
我们使用市售的激光多普勒振动计（LDV）测量了麻醉豚鼠在空气传导声音（ACS）或骨传导振动（BCV）刺激时，暴露的后半规管在矢状面的速度。我们还同时测量了耳石功能，形式为前庭微音（UM）和前庭短潜伏期诱发电位（VsEP）。基于 LDV 测量的黄斑振动水平，UM 对 ACS 和 100-200Hz 之间的 BCV 最为敏感。对于 ACS 刺激，UM 相对于黄斑运动相位的相位在整个频率范围内相对一致，但对于 BCV 刺激，相位变化了几个周期，这表明耳石受体激活的机械模式不同。此外，与 ACS 不同，BCV 在某些频率下会引起明显失真的 UM 和黄斑振动响应，这很可能是由于颅骨的复杂共振。类似于 Corti 器官振动的 LDV 研究，这种方法提供了一种手段来研究后半规管的动态响应，同时测量功能。
