ISSN:1420-3030    

DOI:10.1159/000259184

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The sound-induced travelling wave in the mammalian cochlea is believed to be enhanced and sharpened by a positive-feed-back mechanism, causing the passive, linear growth function of the basilar membrane (BM) to become nonlinear. Based on direct measurements of the receptor potential of isolated outer hair cells, it is shown here how nonlinear BM motion might be due predominantly to the nonlinear growth function of the receptor potential. Since intensity coding in the inner ear is supposed to depend on an interaction of nonlinear BM motion with afferent fibres of different synaptic thresholds, intensity coding is expected to be directly dependent on the mechanoelectrical transduction of outer hair cells (OHC). According to the present experimental data and the feedback concept of outer hair cell action, disruption of the mechanoelectrical transduction of OHC leads to both a reduction of gain and linearizing of the response; that is, to both hearing loss and loudness recruitment.

ISSN:1420-3030    

DOI:10.1159/000259185

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Effects of a tone, not at the best frequency (BF), on the responses of onset units to BF tones were recorded in the ventral cochlear nucleus of the guinea pig. The off-BF tone was at a fixed non-excitatory sound level. When the two tones were gated simultaneously, a marked threshold facilitation was observed; however, no facilitation was observed if the off-BF tone burst was delayed by 5–10 ms. Facilitation in some units declined and was either absent or only just detectable, when the start of the off-BF tone preceded that of the BF by more than 10 ms. However, the responses of the majority of onset units were facilitated when the off-BF tone preceded the BF tone by as much as 20 ms. Similar results were obtained when the roles of the BF and off-BF tones were reversed. These data suggest that depolarization due to BF inputs is of shorter duration than that due to off-BF input

ISSN:1420-3030    

DOI:10.1159/000259199

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A monoclonal antibody (CAR) was raised by in vitro immunisation to a component of the circumferential actin ring that is associated with the apical junctions encircling the cuticular plates of mammalian hair cells. On western blots it bound a protein band at about 42 kD, equivalent to the normal location of actin, but it did not label the paracrystalline bundle of actin filaments in the stereocilia, the complex actin filament gel that forms the cuticular plate or the filamentous actin in the cell cortex. When applied to whole mounts of the auditory sensory epithelium in the guinea pig it provided a clear, unambiguous map of the distribution of inner and outer hair cells. In this respect, it can provide an accurate guide to patterns of hair cell differentiation and repair. CAR cross-reacted with the membrane-associated cytoskeleton in selected cells from a wide range of other tissues.

ISSN:1420-3030    

DOI:10.1159/000259200

出版商:S. Karger AG    

年代:1996

数据来源: Karger