The Development of Cochlear Function

Rübsamen, Rudolf; Lippe, William R.

doi:10.1007/978-1-4612-2186-9_5

Cited by 45 publications

(30 citation statements)

References 256 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the onset of hearing, the cochlea builds up an endocochlear potential (EP) in the scala media (25,28) that contributes to the driving force for mechanoelectrical transduction. Na, K-ATPase subunits expressed in the stria vascularis that may contribute to generation of the EP have been suggested to be regulated by T3 (29).…”

Section: Resultsmentioning

confidence: 99%

Thyroid hormone receptor β-dependent expression of a potassium conductance in inner hair cells at the onset of hearing

Rüsch

Erway

Oliver

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

109

View full text Add to dashboard Cite

To elucidate the role of thyroid hormone receptors (TRs) ␣1 and ␤ in the development of hearing, cochlear functions have been investigated in mice lacking TR␣1 or TR␤. TRs are ligand-dependent transcription factors expressed in the developing organ of Corti, and loss of TR␤ is known to impair hearing in mice and in humans. Here, TR␣1-deficient (TR␣1 ؊/؊ ) mice are shown to display a normal auditory-evoked brainstem response, indicating that only TR␤, and not TR␣1, is essential for hearing. Because cochlear morphology was normal in TR␤ ؊/؊ mice, we postulated that TR␤ regulates functional rather than morphological development of the cochlea. At the onset of hearing, inner hair cells (IHCs) in wild-type mice express a fast-activating potassium conductance, I K,f , that transforms the immature IHC from a regenerative, spiking pacemaker to a high-frequency signal transmitter. Expression of I K,f was significantly retarded in TR␤ ؊/؊ mice, whereas the development of the endocochlear potential and other cochlear functions, including mechanoelectrical transduction in hair cells, progressed normally.

show abstract

Section: Resultsmentioning

confidence: 99%

Thyroid hormone receptor β-dependent expression of a potassium conductance in inner hair cells at the onset of hearing

Rüsch

Erway

Oliver

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

109

View full text Add to dashboard Cite

show abstract

“…This gradient decrease could be explained by a number of mechanisms, such as change in cochlear place-code during development (Rubsamen and Lippe 1998) or reorganization of the place-code at one or more subcortical stations (Romand 1997). However, the most parsimonious explanation is simply that the cortex increases in volume during development.…”

Section: Tonotopic Gradientmentioning

confidence: 99%

Spatial Organization of Frequency Response Areas and Rate/Level Functions in the Developing AI

Bonham

Cheung²,

Godey³

et al. 2004

Journal of Neurophysiology

View full text Add to dashboard Cite

. Spatial organization of frequency response areas and rate/level functions in the developing AI. J Neurophysiol 91: 841-854, 2004. First published October 8, 2003 10.1152/jn.00017.2003. The current study was conducted to extend our understanding of changes in spatial organization and response properties of cortical neurons in the developing mammalian forebrain. Extracellular multiunit responses to tones were recorded from a dense array of penetrations covering entire isofrequency contours in the primary auditory cortex (AI) of pentobarbital anesthetized kittens. Ages ranged from postnatal day 14 (P14), shortly after acquisition of normal auditory response thresholds, through postnatal day 111 (P111), when the kittens were largely mature. Spatial organization of the AI was tonotopically ordered by P14. The tonotopic gradient decreased with chronological maturation. At P14 the gradient was about 3.5 kHz/mm. By P111 it had declined to about 2.5 kHz/mm, so that the cortical region encompassing a fixed 3-to 15-kHz frequency range enlarged along its posterior-anterior dimension. Response properties of developing AI neurons changed in both frequency selectivity and intensity selectivity. The mean frequency tuning bandwidth increased with age. Initially, tuning bandwidths were narrow throughout the entire AI. With progressive maturation, broader bandwidths were observed in areas dorsal and ventral to a central region in which neurons remained narrowly tuned. The resulting spatial organization of tuning bandwidth was similar to that reported in adult cats. The majority of recording sites manifested nonmonotonic rate/level functions at all ages. However, the proportion of sites with monotonic rate/level functions increased with age. No spatial organization of rate/level functions (monotonic and nonmonotonic) was observed through P111. The relatively late development of bandwidth tuning in the AI compared with the early presence of tonotopic organization suggests that different developmental processes are responsible for structuring these two dimensions of acoustic selectivity. I N T R O D U C T I O NThe primary auditory cortex (AI) is organized topographically and reflects the spatial layout of the sensory surface (Merzenich and Brugge 1973;Reale and Imig 1980). The AI representation comprises tonotopically arrayed isofrequency domains resulting in an inhomogeneous, systematic spatial distribution of characteristic frequency (CF; i.e., the frequency of a tone burst to which a neuron is most sensitive).In the adult cat, the spatial distributions of other response parameters are also nonhomogeneous, such that neighboring locations within the AI often exhibit similar tuning bandwidths (Schreiner and Mendelson 1990) and rate/level functions (Clarey et al. 1994;Imig et al. 1990;Phillips et al. 1985Phillips et al. , 1994. Tuning bandwidths of local cell clusters in the central portion of the mature AI are sharper than bandwidths in flanking ventral and dorsal regions (Schreiner and Mendelson 1990). The spatial distribution of ...

show abstract

“…They are born between E12-E14 (Ruben 1967;Kelley et al 1993) and differentiation proceeds from the base to the apex of the cochlea with a delay of ∼2-3 d (Lim and Anniko 1985;Zine and Romand 1996;Nishida et al 1998). Cells mature around postnatal days P12-P14, when the ear becomes functional (Rubsamen and Lippe 1997;Kros et al 1998). Additional hair cells can be recruited during this period (Kelley et al 1993;, but there is no evidence for sensory cell replacement after P14.…”

mentioning

confidence: 99%

Transcript Profiling of Functionally Related Groups of Genes During Conditional Differentiation of a Mammalian Cochlear Hair Cell Line

Rivolta¹,

Halsall²,

Johnson³

et al. 2002

Genome Res.

View full text Add to dashboard Cite

We have used Affymetrix high-density gene arrays to generate a temporal profile of gene expression during differentiation of UB/OC-1, a conditionally immortal cell line derived from the mouse cochlea. Gene expression was assessed daily for 14 days under differentiating conditions. The experiment was replicated in two separate populations of cells. Profiles for selected genes were correlated with those obtained by RT-PCR, TaqMan analysis, immunoblotting, and immunofluorescence. The results suggest that UB/OC-1 is derived from a population of nonsensory epithelial cells in the greater epithelial ridge that have the potential to differentiate into a hair-cell-like phenotype, without the intervention of Math1. Elements of the Notch signaling cascade were identified, including the receptor Notch3, with a transient up-regulation that suggests a role in hair cell differentiation. Several genes showed a profile similar to Notch3, including the transcriptional co-repressor Groucho1. UB/OC-1 also expressed Me1, a putative partner of Math1 that may confer competence to differentiate into hair cells. Cluster analysis revealed expression profiles for neural guidance genes associated with Gata3. The temporal dimension of this analysis provides a powerful tool to study genetic mechanisms that underlie the conversion of nonsensory epithelial cells into hair cells

show abstract

The Development of Cochlear Function

Cited by 45 publications

References 256 publications

Thyroid hormone receptor β-dependent expression of a potassium conductance in inner hair cells at the onset of hearing

Thyroid hormone receptor β-dependent expression of a potassium conductance in inner hair cells at the onset of hearing

Spatial Organization of Frequency Response Areas and Rate/Level Functions in the Developing AI

Transcript Profiling of Functionally Related Groups of Genes During Conditional Differentiation of a Mammalian Cochlear Hair Cell Line

Contact Info

Product

Resources

About