Cochlea

OBJECTIVE: The distribution and role of NMDA receptors is unclear in the afferent signaling complex of the cochlea. The present study aimed to examine the distribution of NMDA receptors in cochlear afferent signaling complex of the adult mouse, and their relationship with ribbon synapses of inner hair cells (IHCs) and GABAergic efferent terminals of the lateral olivocochlear (LOC). METHODS: Immunofluorescence staining in combination with confocal microscopy was used to investigate the distribution of glutamatergic NMDA and AMPA receptors in afferent terminals of SGNs, and their relationship with ribbon synapses of IHCs and GABAergic efferent terminals of LOC...

INTRODUCTION: Hair cells (HCs) of the cochlea are responsible for sound transduction and hearing perception in mammals. Genetic mutations in the transcription factor Pou4f3 cause non-syndromic autosomal dominant hearing loss in humans (DFNA15) which varies in the age of onset depending on the individual mutation. Mouse models with germline deletion or mutations in Pou4f3 have previously demonstrated its critical role in the maturation and survival of cochlear HCs during embryonic development...

SNHL in children is an important issue. Cochlear implant is a highly technological device that is surgically inserted in the cochlea to solve this issue. To evaluate types of anomalies of the inner ear in children with sensorineural hearing loss in a tertiary care hospital and confirm that the routine MRI, MR cisternography and HRCT provides the surgeon with the imaging finding and criteria of patients candidates for CI. Patients and method: 600 patients with SNHL underwent HRCT and MRI. CT examinations were normal in 457 patients (76...

In a unique exploration of narrative development among Tamil-speaking children, this study delves into the intricacies of linguistic expression, explicitly comparing the microstructure of narratives in two distinct groups: those with hearing differences (HD) and those with normal hearing. A total of 30 children were included in the study, with 15 children in each group, matched for language age between 3-5 years on standard language tests. The children were asked to retell a story they had listened to, and the obtained samples were transcribed verbatim and analyzed for various microstructural elements, including the mean length of utterances, total number of words, number of utterances, and number of different word types...

Type I spiral ganglion neurons (SGNs) convey sound information to the central auditory pathway by forming synapses with inner hair cells (IHCs) in the mammalian cochlea. The molecular mechanisms regulating the formation of the post-synaptic density (PSD) in the SGN afferent terminals are still unclear. Here, we demonstrate that brain-specific angiogenesis inhibitor 1 (BAI1) is required for the clustering of AMPA receptors GluR2-4 (glutamate receptors 2-4) at the PSD. Adult Bai1-deficient mice have functional IHCs but fail to transmit information to the SGNs, leading to highly raised hearing thresholds...

Ototoxicity is a devastating direct, irreversible side effect of platinum use in children with cancer, with its consequent effect on speech, language and social development, quality of life and adult productivity. Cisplatin, an essential chemotherapeutic agent for the treatment of solid tumors in children, is a DNA cross-linking agent. Which causes hearing loss in 50-70% of cisplatin treated children. Fortunately, to prevent hearing loss, sodium thiosulfate (STS), which binds to cisplatin, and reduces the superoxides in both tumor and outer hair cells of the cochlea has now been discovered to be an effective and safe otoprotectant if administered correctly...

OBJECTIVE: This study aimed to determine if the major public awareness campaign for cochlear implants 'International Cochlear Implant Day' influenced national and international public interest as measured by internet search activity. METHODS: Weekly search volume data in the United States, Canada, Australia, Germany, United Kingdom, Brazil, India, Japan, and a 'Worldwide' group for the search topic 'cochlear implant' was collected from Google Trends over a 5-year period (2017-2021)...

To reach the energy efficiency and the computing capability of biological neural networks, novel hardware systems and paradigms are required where the information needs to be processed in both spatial and temporal domains. Resistive switching memory (RRAM) devices appear as key enablers for the implementation of large-scale neuromorphic computing systems with high energy efficiency and extended scalability. Demonstrating a full set of spatiotemporal primitives with RRAM-based circuits remains an open challenge...

Cochlear implants (CIs) are considered the standard-of-care treatment for profound sensory-based hearing loss. Several groups have proposed computational models of the cochlea in order to study the neural activation patterns in response to CI stimulation. However, most of the current implementations either rely on high-resolution histological images that cannot be customized for CI users or CT images that lack the spatial resolution to show cochlear structures. In this work, we propose to use a deep learning-based method to obtain μCT level tissue labels using patient CT images...

Efferent feedback to the mammalian cochlea includes cholinergic medial olivocochlear neurons (MOCs) that release ACh to hyperpolarize and shunt the voltage change that drives electromotility of outer hair cells (OHCs). Via brainstem connectivity, MOCs are activated by sound in a frequency- and intensity-dependent manner, thereby reducing the amplification of cochlear vibration provided by OHC electromotility. Among other roles, this efferent feedback protects the cochlea from acoustic trauma. Lesion studies, as well as a variety of genetic mouse models, support the hypothesis of efferent protection from acoustic trauma...

Cochlear implants (CIs) are neuroprosthetics that can provide a sense of sound to people with severe-to-profound hearing loss. A CI contains an electrode array (EA) that is threaded into the cochlea during surgery. Recent studies have shown that hearing outcomes are correlated with EA placement. An image-guided cochlear implant programming technique is based on this correlation and utilizes the EA location with respect to the intracochlear anatomy to help audiologists adjust the CI settings to improve hearing...

PURPOSE: This study investigates the effect of parallel stimulus presentation on the place specificity of the auditory brainstem response (ABR) in human listeners. Frequency-specific stimuli do not guarantee a response place on the cochlea corresponding only to that characteristic frequency - especially for brief and high-level stimuli. Masking techniques can ensure place specific responses, and prior modeling has suggested parallel presentation of frequency-specific stimuli improves place specificity...

Hearing is an essential sensation, and its deterioration leads to a significant decrease in the quality of life. Thus, great efforts have been made by otologists to preserve and recover hearing. Our knowledge regarding the field of otology has progressed with advances in technology, and otologists have sought to develop novel approaches in the field of otologic surgery to achieve higher hearing recovery or preservation rates. This requires knowledge regarding the anatomy of the temporal bone and the physiology of hearing...

OBJECTIVES: Objective measurements to predict the position of a cochlear electrode during cochlear implantation surgery may serve to improve the surgical technique and postoperative speech outcome. There is evidence that electrically evoked compound action potentials (ECAP) are a suitable approach to provide information about the site of stimulation. This study aims to contribute to the knowledge about the association between the intraoperative intracochlear ECAP characteristics and the site of stimulation...

BACKGROUND: This study aimed to determine whether proton craniospinal irradiation (CSI) decreased the dose to normal tissue and resulted in less toxicity than photon CSI for adult patients. METHODS: This single-institution retrospective analyzed differences in radiation doses, acute toxicity, and cost between proton and CSI for adult medulloblastoma patients. RESULTS: Of 39 total patients, 20 were treated with photon CSI prior to 2015, and 19 were treated with proton CSI thereafter...

Hearing loss is a major disability in everyday life and therapeutic interventions to protect hearing would benefit a large portion of the world population. Here we found that mice devoid of the protein kinase suppressor of RAS 1 (KSR1) in their tissues (germline KO mice) exhibit resistance to both cisplatin- and noise-induced permanent hearing loss compared to their wild-type KSR1 littermates. KSR1 is a scaffold protein that brings in proximity the mitogen-activated protein kinase (MAPK) proteins BRAF, MEK1/2 and ERK1/2 and assists in their activation through a phosphorylation cascade induced by both cisplatin and noise insults in the cochlear cells...

Acute noise-induced loss of synapses between inner hair cells (IHCs) and auditory nerve fibers (ANFs) has been documented in several strains of mice, but the extent of post-exposure recovery reportedly varies dramatically. If such inter-strain heterogeneity is real, it could be exploited to probe molecular pathways mediating neural remodeling in the adult cochlea. Here, we compared synaptopathy repair in CBA/CaJ vs. C57BL/6J, which are at opposite ends of the reported recovery spectrum. We evaluated C57BL/6J mice 0 h, 24 h, 2 wks or 8 wks after exposure for 2 h to octave-band noise (8-16 kHz) at either 90, 94 or 98 dB SPL, to compare with analogous post-exposure results in CBA/CaJ at 98 or 101 dB...

OBJECTIVE: The objective was to determine the effects of older age on hearing preservation after cochlear implantation (CI), and whether steroids improve hearing preservation in older animals. We hypothesized greater hearing preservation would be observed in (1) young animals compared to older animals and (2) older animals receiving steroids compared to no steroids. The secondary objective was to assess levels of fibrosis utilizing optical coherence tomography (OCT). STUDY DESIGN: Experimental Animal Study...

BACKGROUND: Cochlear-implant electrode arrays (EAs) are currently inserted with limited feedback, and impedance sensing has recently shown promise for EA localisation. METHODS: We investigate the use of impedance sensing to infer the progression of an EA during insertion. RESULTS: We show that the access resistance component of bipolar impedance sensing can detect when a straight EA reaches key anatomical locations in a plastic cochlea and when each electrode contact enters/exits the cochlea...

OBJECTIVE: To assess trauma patterns associated with the insertion of lateral wall electrode arrays. The study focused on 3 categories-scala tympani (ST), intermediate, and scala vestibuli (SV)-to identify traumatic patterns and contributing factors. STUDY DESIGN: Retrospective study. SETTING: Data from 106 cochlear implant recipients at a tertiary otologic center. METHODS: Demographic and surgical data were collected from recipients who underwent cochlear implantation manually and with RobOtol®...