Russell I J, Richardson G P
MRC Neurophysiology Group, School of Biological Sciences, University of Sussex, Falmer, Brighton, U.K.
Hear Res. 1987 Nov;31(1):9-24. doi: 10.1016/0378-5955(87)90210-3.
Organotypic explant cultures were prepared from the cochleas of 1 to 3 day post-natal mice and maintained in vitro for up to 5 days. The hair cells retain morphological integrity for the duration of the culture period although they exhibit embryological features such as a kinocilium and additional microvilli on their apical surfaces. The resting membrane potentials of mouse inner hair cells (IHCs) in vitro are similar to those of guinea-pig IHCs in vivo but the membrane potentials of outer hair cells (OHCs) in the mouse cochlea in vitro are less polarized than the resting membrane potentials of OHCs in the basal turn of the guinea-pig cochlea in vivo. The voltage responses of IHCs and OHCs to sinusoidal displacements of their stereocilia are similar to each other in waveform and dynamic range, although the responses of IHCs are larger than those of OHCs. The relationship between transducer conductance and stereocilia displacement in IHCs and OHCs is non-linear and largely accounts for the depolarizing asymmetry of the voltage response. The receptor potentials of IHCs and OHCs reverse close to 0 mV indicating that the transducer conductance is non-selective for cations. The voltage responses of IHCs and OHCs to intracellular current injection rectify when the membrane potentials are more depolarized than about -30 mV. This rectification is most pronounced in OHCs. OHCs also exhibit a time-dependent, voltage-sensitive conductance although they do not behave as electrical resonators.
从出生后1至3天的小鼠耳蜗制备器官型外植体培养物，并在体外维持长达5天。毛细胞在培养期内保持形态完整性，尽管它们表现出胚胎学特征，如动纤毛和顶端表面的额外微绒毛。体外培养的小鼠内毛细胞（IHC）的静息膜电位与体内豚鼠内毛细胞的相似，但体外小鼠耳蜗外毛细胞（OHC）的膜电位极化程度低于体内豚鼠耳蜗基底转外毛细胞的静息膜电位。IHC和OHC对其静纤毛正弦位移的电压响应在波形和动态范围内彼此相似，尽管IHC的响应大于OHC的响应。IHC和OHC中换能器电导与静纤毛位移之间的关系是非线性的，这在很大程度上解释了电压响应的去极化不对称性。IHC和OHC的受体电位在接近0 mV时反转，表明换能器电导对阳离子无选择性。当膜电位比约-30 mV更去极化时，IHC和OHC对细胞内电流注入的电压响应会整流。这种整流在OHC中最为明显。OHC也表现出时间依赖性、电压敏感的电导，尽管它们不作为电谐振器。
