Sichel Jean-Yves, Perez Ronen, Freeman Sharon, Sohmer Haim
Department of Otolaryngology-Head & Neck Surgery, Hadassah University Hospital, Jerusalem, Israel.
J Basic Clin Physiol Pharmacol. 2005;16(2-3):81-99. doi: 10.1515/jbcpp.2005.16.2-3.81.
In order to assess the mechanisms of cochlear activation, the cochlear fluids of one cochlea of a guinea-pig (I) were coupled to those of a cochlea of a second guinea-pig (II) by means of a saline-filled narrow bore tube, the ends of which were placed in the fluids around the opened round windows of both cochleae, thus joining the two cochleae from two different animals into a single, larger, unsealed fluid system. In response to air-conducted sound stimulation of cochlea I, auditory nerve-brainstem evoked responses could be recorded in animal II, not only when the coupling tube was filled with saline, but also when it was filled with ultrasound gel (viscosity 100,000 greater than that of water), when there was a very large hole encompassing a relatively large expanse of the cochlear shell of animal I, and even when animal I was no longer alive. The necessary control experiments were performed. Therefore, it is suggested that at low stimulus intensities, the passive, incoming basilar membrane traveling wave may not activate the cochlea. Instead the fluid pressures (condensation/rarefactions) induced in the cochlear fluids by vibrations of the stapes footplate may be adequate to directly activate the outer hair cells, which then generate an active component of basilar membrane displacement.
为了评估耳蜗激活的机制，通过一根充满盐水的细管，将一只豚鼠（I）一侧耳蜗的淋巴液与另一只豚鼠（II）一侧耳蜗的淋巴液相连，细管两端置于两只耳蜗开放圆窗周围的淋巴液中，从而将来自两只不同动物的耳蜗连接成一个更大的、未密封的单一淋巴液系统。对耳蜗I进行气导声音刺激时，不仅在连接管充满盐水时，而且在充满超声凝胶（粘度比水大100,000倍）时，当动物I的耳蜗壳有一个相对较大区域的非常大的孔洞时，甚至当动物I不再存活时，均可在动物II中记录到听神经-脑干诱发反应。进行了必要的对照实验。因此，有人提出，在低刺激强度下，被动传入的基底膜行波可能不会激活耳蜗。相反，镫骨足板振动在耳蜗淋巴液中引起的流体压力（压缩/稀疏）可能足以直接激活外毛细胞，然后外毛细胞产生基底膜位移的主动成分。
