直流电脉冲刺激豚鼠耳蜗基底膜振动研究 |
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引用本文: | 郭梦和,任田英,AlfredL.Nutall. 直流电脉冲刺激豚鼠耳蜗基底膜振动研究[J]. 中华耳鼻咽喉头颈外科杂志, 1997, 0(5) |
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作者姓名: | 郭梦和 任田英 AlfredL.Nutall |
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作者单位: | 第四军医大学西京医院耳鼻咽喉科,美国俄勒岗医科大学听力研究中心 |
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摘 要: | 为了在活体上研究哺乳类动物耳蜗基底膜的电-机械特性,将一对铂-铱电极分别置于30只豚鼠耳蜗底回的前庭阶和鼓阶。用矩形直流脉冲电刺激蜗管,用激光多普勒测速仪测定电刺激诱发的耳蜗基底膜振动的幅度和速度。结果表明,在听敏度正常豚鼠的耳蜗,电刺激可诱发基底膜向正电极方向位移,其位移波形类似于电脉冲的矩形波。在矩形脉冲的起始沿和结束沿,由于外毛细胞的瞬态反应,可诱发与该部位特征频率一致的共振运动。据分析,这一共振运动是外毛细胞的主动耗能过程,并由耳蜗放大器参与。在听力受损的耳蜗,直流电刺激仍能引起基底膜的位移,但振铃运动明显减少或消失。这可能是受损毛细胞的能量代谢障碍所致。直流电刺激诱发的基底膜振动与声波一样,可通过行波沿基底膜向其它部位传输,这一特性奠定了电听觉和耳声发射的生理基础。
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关 键 词: | 耳蜗 基底膜 振动 |
Research on basilar membrane vibration of guinea pigs elicited by direct current pulse |
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Abstract: | To investigate the electromotility of basilar membrane (BM) of guinea pigs in vivo, a couple of Platinum iridium wire electrodes were placed into holes drilled in the scala vestibuli and scala tympani on the basal turn of cochlea separately. The organ of Corti was stimulated with rectangular direct current pulses. The displacement and velocity of BM were measured with Laser Doppler velocimeter. The results indicated that the displacement of BM elicited by current moved toward the scala where positive current was injected . The waveform of BM displacement was corresponding to the rectangular pulse of electric current step. Ringing responses could be seen at the onset and offset of current pulse that was the transient responses of outer hair cells. The frequency of the ringing was the same as that of characteristic frequency of partition in BM. It is supposed that the ringing of BM is an active process of depletive energy and participate with cochlear amplifier. In the insensitive cochlea or dead animal, direct current can still elicit a BM displacement but the ringing response is decreased or disappeared. This phenomenon is probably because of metabolic disturbance in damaged outer hair cells. The BM vibration induced by direct current is similar to that of induced by acoustic stimulation, which can transfer to other partition of BM by traveling wave. This characteristic has laid a foundation of electromotile hearing and electrically evoked otoacoustic emission. |
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Keywords: | Cochlea Basilar membrane Vibration |
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