31,459 research outputs found
A Partial Ossicular Replacement Prosthesis With a Concentric Ball Joint in the Headplate
No full textObjective
In passive middle ear prosthetics, rigid implants have proven successful in reconstructing the ossicular chain. However, these cannot fully replicate the physiology of the ossicular chain. Pressure fluctuations cause high stresses in rigid passive prostheses, which can result in dislocation, protrusion, and pre-tension in the annular ligament resulting in unsatisfactory hearing results.
Methods
In collaboration with MED-EL, we developed a new passive middle ear prosthesis that features a balanced, centered ball joint between the headplate and shaft of the prosthesis. We compared the sound transmission properties of this new prosthesis with those of a standard rigid prosthesis. Using Laser-Doppler-Vibrometry, we measured the sound-induced velocity of the stapes footplate relative to a given acoustic stimulus.
Results
The new prosthesis showed equivalent sound transmission characteristics compared to the rigid prosthesis, whereas retaining the ability to compensate for pressure fluctuations due to its ball joint. This ensures good transmission properties even during displacements of the tympanic membrane.
Conclusion
This development is a further step toward a physiological reconstruction of the ossicular chain.MED-EL Medical Electronics https://doi.org/10.13039/50110001885
NompC TRP Channel Is Essential for Drosophila Sound Receptor Function
No full textSummaryThe idea that the NompC TRPN1 channel is the Drosophila transducer for hearing has been challenged by remnant sound-evoked nerve potentials in nompC nulls [1–5]. We now report that NompC is essential for the function of Drosophila sound receptors and that the remnant nerve potentials of nompC mutants are contributed by gravity/wind receptor cells. Ablating the sound receptors reduces the amplitude and sensitivity of sound-evoked nerve responses, and the same effects ensued from mutations in nompC. Ablating the sound receptors also suffices to abolish mechanical amplification, which arises from active receptor motility [6, 7], is linked to transduction [8], and also requires NompC [9]. Calcium imaging shows that the remnant nerve potentials in nompC mutants are associated with the activity of gravity/wind receptors and that the sound receptors of the mutants fail to respond to sound. Hence, Drosophila sound receptors require NompC for mechanical signal detection and amplification, demonstrating the importance of this transient receptor potential channel for hearing and reviving the idea that the fly's auditory transducer might be NompC
Recent advances in cochlear hair cell nanophysiology: subcellular compartmentalization of electrical signaling in compact sensory cells
No full textIn recent years, genetics, physiology, and structural biology have advanced into the molecular details of the sensory physiology of auditory hair cells. Inner hair cells (IHCs) and outer hair cells (OHCs) mediate two key functions: active amplification and non-linear compression of cochlear vibrations by OHCs and sound encoding by IHCs at their afferent synapses with the spiral ganglion neurons. OHCs and IHCs share some molecular physiology, e.g. mechanotransduction at the apical hair bundles, ribbon-type presynaptic active zones, and ionic conductances in the basolateral membrane. Unique features enabling their specific function include prestin-based electromotility of OHCs and indefatigable transmitter release at the highest known rates by ribbon-type IHC active zones. Despite their compact morphology, the molecular machineries that either generate electrical signals or are driven by these signals are essentially all segregated into local subcellular structures. This review provides a brief account on recent insights into the molecular physiology of cochlear hair cells with a specific focus on organization into membrane domains
Die Entwicklung einer passiven Mittelohrprothese mit konzentrischem Mikrokugelgelenk in der Kopfplatte – erste Ergebnisse im Felsenbeinexperiment
No full textThe development of a passive middle ear prosthesis with concentric microsphere joint in the head plate – first results from temporal bone experiments
No full textNOMPC gating spring - data repository
No full textThis data repository contains the data used in: Hehlert & Effertz et al., 202
Antennal hearing in insects – New findings, new questions
No full textMosquitoes, certain Drosophila species, and honey bees use Johnston's organ in their antennae to detect the wing-beat sounds of conspecifics. Recent studies on these insects have provided novel insights into the intricacies of insect hearing and sound communication, with main discoveries including transduction and amplification mechanisms as known from vertebrate hearing, functional and molecular diversifications of mechanosensory cells, and complex mating duets that challenge the frequency-limits of insect antennal ears. This review discusses these recent advances and outlines potential avenues for future research. (C) 2010 Elsevier B.V. All rights reserved
Thomas Grisell letter to Thomas Rotch, 2nd mo 19th 1823
No full textThomas Grisell's letter reached the Rotch household several months before the unexpected death of Thomas Rotch in August, 1823. This is the last letter of the series and presumably the author learned of his friend's death before another letter was penned. 7.95" x 10" (20.2 by 25.5 cm
Nitinol in Passive Ossicular Reconstruction—First Results From Temporal Bone Experiments
No full text- …
