VOLTAGE OSCILLATIONS AND IONIC CONDUCTANCES IN HAIR-CELLS ISOLATED FROM THE ALLIGATOR COCHLEA
VOLTAGE OSCILLATIONS AND IONIC CONDUCTANCES IN HAIR-CELLS ISOLATED FROM THE ALLIGATOR COCHLEA
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DOI：
10.1007/bf00603947
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发表时间：
1988-01-01
影响因子：
2.1
通讯作者：
EVANS, MG
中科院分区：
文献类型：
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作者：
FUCHS, PA;EVANS, MG
用酶消化法和机械分离法从扬子鳄耳蜗顶半部的特定区域分离出高大毛细胞。采用密闭全细胞记录技术对单个细胞进行电压钳制和电流钳制。大多数从耳蜗尖分离的毛细胞在注入电流时产生缓慢再生的去极化或钠动作电位，而从更底部区域分离的毛细胞通常产生电压振荡(振铃)以响应去极化电流注入，这是电共振的迹象。不同细胞的共振频率在50~157赫兹之间。高频细胞往往比低频细胞有更大和更快激活的外向电流。所有毛细胞均存在内向钙电流和外向钙激活钾电流。此外，经常可以看到内向整流电流和小的瞬时外向电流。因此，我们得出结论，鳄鱼毛细胞中存在一种电调机制。讨论了离子电导在形成毛细胞对电流注入的反应中的作用，以及这些电反应对耳蜗功能的可能贡献。
Tall hair cells were isolated by enzymatic and mechanical dissociation from selected regions of the apical half of the alligator (Alligator mississippiensis) cochlea. Single cells were subjected to voltage-clamp and current-clamp using the tight-seal whole-cell recording technique. Most hair cells isolated from the apex of the cochlea produced slowly regenerative depolarizations or Na action potentials during current injection, whereas hair cells isolated from more basal regions usually produced voltage oscillations (ringing) in response to depolarizing current injection, an indication of electrical resonance. Resonant frequencies ranged from 50 to 157 Hz in different cells. The higher-frequency cells tended to have larger and more rapidly activating outward currents than did the lower-frequency cells. An inward Ca current and an outward Ca-activated K current were present in all hair cells. In addition, an inwardly rectifying current and a small, transient outward current were often seen. Thus, we conclude that an electrical tuning mechanism is present in alligator hair cells. The role of the ionic conductances in shaping hair cell responses to current injection, and the possible contributions of these electrical responses to cochlear function are discussed.