Vestibular Research Laboratory, School of Psychology, The University of Sydney, NSW, Sydney, 2006, Australia.
Exp Brain Res. 2011 May;210(3-4):347-52. doi: 10.1007/s00221-010-2499-5. Epub 2010 Nov 28.
This study tested whether air-conducted sound and bone-conducted vibration activated primary vestibular afferent neurons and whether, at low levels, such stimuli are specific to particular vestibular sense organs. In response to 500 Hz bone-conducted vibration or 500 Hz air-conducted sound, primary vestibular afferent neurons in the guinea pig fall into one of two categories--some neurons show no measurable change in firing up to 2 g peak-to-peak or 140 dB SPL. These are semicircular canal neurons (regular or irregular) and regular otolith neurons. In sharp contrast, otolith irregular neurons show high sensitivity: a steep increase in firing as stimulus intensity is increased. These sensitive neurons typically, but not invariably, were activated by both bone-conducted vibration and air-conducted sound, they originate from both the utricular and saccular maculae, and their sensitivity underpins new clinical tests of otolith function.
这项研究旨在测试空气传导声音和骨传导振动是否能激活初级前庭传入神经元，以及在低强度刺激下，这些刺激是否特定于特定的前庭感觉器官。在豚鼠中，对 500Hz 骨传导振动或 500Hz 空气传导声音的反应中，初级前庭传入神经元可分为两类——有些神经元在高达 2g 峰峰值或 140dB SPL 的情况下，其放电没有可测量的变化。这些是半规管神经元（规则或不规则）和规则耳石神经元。相比之下，耳石不规则神经元表现出高灵敏度：随着刺激强度的增加，放电急剧增加。这些敏感神经元通常（但并非总是）同时被骨传导振动和空气传导声音激活，它们源自椭圆囊斑和球囊斑，它们的敏感性为耳石功能的新临床测试提供了依据。
