Hearing ResearchPub Date : 2025-08-04DOI: 10.1016/j.heares.2025.109382
Samuel Söderqvist , Ville Sivonen , Alexander Huber , Saku T. Sinkkonen , Leanne Sijgers
{"title":"Intracochlear electric potential measurements for estimating electrode array position in cochlear implantation: The in vivo utility of an ex vivo model","authors":"Samuel Söderqvist , Ville Sivonen , Alexander Huber , Saku T. Sinkkonen , Leanne Sijgers","doi":"10.1016/j.heares.2025.109382","DOIUrl":"10.1016/j.heares.2025.109382","url":null,"abstract":"<div><h3>Introduction</h3><div>Stimulation of cochlear implant electrodes generates intracochlear electric potentials. The local electric potentials can be assessed using <em>e.g.</em> transimpedance matrix (TIM) and four-point impedance (Z<sub>fp</sub>). Both of these measurements are dependent on the cochlear dimensions and the distance between the electrode and the medial wall of the scala tympani (d<sub>EM</sub>). In a recent temporal bone study, a model based on electric potential measurements gave good predictions of scalar cross-sectional area (A<sub>scala</sub>) and d<sub>EM</sub>. The purpose of this study was to further improve this model and evaluate its clinical usefulness. To this end, the intraoperative TIM and Z<sub>fp</sub> measurements from cochlear implant patients were used as independent variables in the model to predict their A<sub>scala</sub> and d<sub>EM</sub> at each electrode contact, which were then compared to those measured from postoperative cone-beam computed tomography (CBCT) images.</div></div><div><h3>Methods</h3><div>In an earlier study, six cadaveric temporal bones were sequentially implanted with three different electrode arrays: a lateral-wall electrode array, Slim Straight, and two precurved perimodiolar electrode arrays, Contour Advance and Slim Modiolar (Cochlear Ltd, Sydney, Australia). The TIM and Z<sub>fp</sub> measurements were performed alongside CBCT imaging, from which the A<sub>scala</sub> and d<sub>EM</sub> at each electrode contact were measured. From the TIM measurements, the peak amplitudes and decay rate of the electric potentials (EP<sub>slope</sub>) were computed. In this follow-up study, the statistical modeling of the <em>ex vivo</em> measurements was refined to better account for individual characteristics by employing mixed-effect models to predict the A<sub>scala</sub>s and d<sub>EM</sub>s. Then, <em>in vivo</em> recordings from thirteen patients, of which six were implanted with the Slim Straight and seven with the Contour Advance electrode arrays, were retrospectively analyzed. The A<sub>scala</sub>s and d<sub>EM</sub>s were measured from their postoperative CBCT images in a similar manner to the temporal bones. To validate the mixed-effects models developed with the temporal bone data, the patients’ intraoperative TIM and Z<sub>fp</sub> measurements were used as independent parameters in the models to predict their A<sub>scala</sub>s and d<sub>EM</sub>s. Finally, the TIM and Z<sub>fp</sub> parameters measured <em>in vivo</em> and <em>ex vivo</em> and the measured and predicted A<sub>scala</sub>s and d<sub>EM</sub>s were compared using <em>t</em>-tests. Also, Pearson’s correlation coefficients were computed between the measured and predicted <em>in vivo</em> A<sub>scala</sub>s and d<sub>EM</sub>s.</div></div><div><h3>Results</h3><div>Both the amplitudes, indicating electric potential peaks, and Z<sub>fp</sub>s, reflecting local potential differences, were lower <em>in vivo</em> than <e","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109382"},"PeriodicalIF":2.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-29DOI: 10.1016/j.heares.2025.109373
Nathaniel T. Greene , Theodore F. Argo , James Easter , Tim Walilko , Daniel J. Tollin
{"title":"Corrigendum to “Frequency dependence and harmonic distortion of stapes displacement and intracochlear pressure in response to very high level sounds” [Hearing Research Volume 453 (2024) p.109121]","authors":"Nathaniel T. Greene , Theodore F. Argo , James Easter , Tim Walilko , Daniel J. Tollin","doi":"10.1016/j.heares.2025.109373","DOIUrl":"10.1016/j.heares.2025.109373","url":null,"abstract":"","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"465 ","pages":"Article 109373"},"PeriodicalIF":2.5,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144753213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-29DOI: 10.1016/j.heares.2025.109380
Dorothy W. Pan, Zihan Yang, Wihan Kim, Kevin Biju, Ksenia Gnedeva, Brian E. Applegate, John S. Oghalai
{"title":"Optical coherence tomography imaging demonstrates endolymphatic hydrops in the lateral and posterior semicircular canals in noise-exposed mice","authors":"Dorothy W. Pan, Zihan Yang, Wihan Kim, Kevin Biju, Ksenia Gnedeva, Brian E. Applegate, John S. Oghalai","doi":"10.1016/j.heares.2025.109380","DOIUrl":"10.1016/j.heares.2025.109380","url":null,"abstract":"<div><div>Optical Coherence Tomography (OCT) has been used to characterize cochlear endolymphatic hydrops (ELH) with distention of Reissner’s membrane in mice after noise exposure. Noise exposure has been correlated with vestibular dysfunction, so we hypothesized that noise exposure can lead to ELH in the vestibular system. Little work has been performed using OCT to image the membranous labyrinth in the lateral and posterior semicircular canals (SCCs). We show that OCT with 12.5 µm axial resolution and 13.2 µm lateral resolution can image the SCCs and delineate the membranous labyrinth in anesthetized mice. A high-resolution OCT system with 2.45 µm axial and 3.95 µm lateral resolution provides improved distinction between the endolymphatic and perilymphatic fluid spaces that enables quantification of the endolymph to perilymph (E/P) area ratio in the SCCs. The LSCC E/P ratio in noise exposed mice (5.16 ± 0.67, mean ± standard deviation, <em>n</em> = 12) is significantly increased (<em>p</em> = 0.0014, unpaired Student’s t-test) compared to control mice (4.26 ± 0.41, <em>n</em> = 10). Similarly, the PSCC E/P ratio in noise exposed mice (4.92 ± 0.52, <em>n</em> = 12) is significantly increased (<em>p</em> = 3.65e-6, unpaired Student’s t-test) compared to control mice (4.00 ± 0.37, <em>n</em> = 11). Furthermore, the PSCC and LSCC E/P ratios correlate significantly (R<sup>2</sup> = 0.284, <em>p</em> = 0.0063, linear regression). These data demonstrate that noise exposure leads to increased E/P ratio, a measurement of ELH, in both the LSCC and PSCC in mice, and this corresponds to ELH present in the cochlea after noise exposure. Therefore, noise exposure leads to ELH in both the cochlea and the vestibular system, suggesting a pathway for noise exposure to cause vestibular dysfunction.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109380"},"PeriodicalIF":2.5,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Single-cell RNA sequencing analysis of mouse cochlea identifies a novel proinflammatory CD74+CD14+ macrophage subset in mice with age-related and noise-induced hearing loss","authors":"Min-Yu Wu , An-Hai Chen , Lin-Qiu Li , Ying Yi, Qin Xiong, Kai-Tian Chen, Zhi-Mou Cai, Wen-Bin Lei, Guan-Xia Xiong, Shu-Bin Fang","doi":"10.1016/j.heares.2025.109376","DOIUrl":"10.1016/j.heares.2025.109376","url":null,"abstract":"<div><div>Age-related hearing loss (ARHL) and noise-induced hearing loss (NIHL) are both associated with the activation of immune responses. However, the immune microenvironment within the cochlea in ARHL and NIHL remains poorly understood. Therefore, we profiled the immune cells in ARHL and NIHL using single-cell RNA sequencing analyses. We observed an increase in CD74<sup>+</sup>CD14<sup>+</sup> macrophages (Mφ) in ARHL and NIHL, with this subset being associated with inflammatory pathways, immune cell chemotaxis and other processes that involved in inflammatory responses. ARHL and NIHL are linked to the degeneration of spiral ganglion neurons. We demonstrated enhanced cellular communication between CD74<sup>+</sup>CD14<sup>+</sup> Mφ and spiral ganglion neurons in both conditions, with CD74<sup>+</sup>CD14<sup>+</sup> Mφ being the most interactive immune cells with spiral ganglion neurons in ARHL. In this study, we highlight the common and distinct characteristics of Mφ in ARHL and NIHL, providing new potential therapeutic targets for these two types of hearing loss.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109376"},"PeriodicalIF":2.5,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-22DOI: 10.1016/j.heares.2025.109374
Ismael Arán-Tapia , Guillermo Bastos , Alberto P․ Muñuzuri
{"title":"Optimization of the Yacovino maneuver for superior canal BPPV using numerical simulations","authors":"Ismael Arán-Tapia , Guillermo Bastos , Alberto P․ Muñuzuri","doi":"10.1016/j.heares.2025.109374","DOIUrl":"10.1016/j.heares.2025.109374","url":null,"abstract":"<div><div>We evaluated the effectiveness of the original Yacovino maneuver (YM) for treating superior canal benign paroxysmal positional vertigo (SC-BPPV) using numerical simulations and proposed modifications to enhance its efficacy. A high-resolution three-dimensional micro-computed tomography (μCT) reconstruction of a human membranous labyrinth was used to simulate the BPPV condition. Endolymphatic fluid dynamics were modeled by solving the Navier–Stokes equations, and otoconia of varying sizes (3–30 µm) were introduced as Lagrangian particles. Their displacement was tracked using a superior canal-centric polar coordinate system. Two maneuver protocols were simulated: the original YM and a modified version with adjusted rotational angles and a 30-second resting interval per step. The original YM resulted in otoconia trapping in the ampulla and canal switching, limiting its effectiveness. In contrast, the modified YM—in which the patient lies face down with a 50° head flexion in the initial step, followed by optimized subsequent rotations—significantly improved otoconia migration toward the utricular macula. Longer resting times further enhanced the displacement of smaller particles without compromising maneuver safety. These findings suggest that the modified YM is a safe and effective alternative for SC-BPPV treatment. Tailoring rotation angles based on anatomical variability may improve outcomes, though clinical validation is still required.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109374"},"PeriodicalIF":2.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-22DOI: 10.1016/j.heares.2025.109348
Julia Veloso de Oliveira, Nora M. Weiss, Wilhelm Wimmer
{"title":"Comprehensive decomposition of cochlear implant electrode impedances","authors":"Julia Veloso de Oliveira, Nora M. Weiss, Wilhelm Wimmer","doi":"10.1016/j.heares.2025.109348","DOIUrl":"10.1016/j.heares.2025.109348","url":null,"abstract":"<div><div>Impedance telemetry is a routine procedure in cochlear implant care, providing insights into the electrode–tissue interface. Analyzing its electrical characteristics helps assess patient outcomes by accounting for implant-specific and tissue-related factors. This work introduces a method to estimate the electrical components of an impedance model for a detailed characterization of electrode impedances. Our approach relies on clinical software, requiring no modifications to standard measurement protocols. A mathematical model describing the total impedance as a function of the pulse duration was introduced. By fitting it to impedance recordings with varying pulse durations, the Warburg capacitance and Faradaic resistance were estimated. The current return path was modeled as a non-leaky resistive transmission line, and its individual resistances were calculated from the voltage matrix. Results were compared to an established geometric approach for estimating near-field and far-field impedance subcomponents. We observed a strong agreement between the geometric method and the proposed approach, indicated by a mean difference of 155<!--> <!-->Ω (near-field) and -107<!--> <!-->Ω (far-field) and a relative mean error of 4% and 18% respectively. The evolution of the electrical components over time is consistent with previous studies and may serve as a valuable tool for characterizing and monitoring the dynamic behavior of the electrode–electrolyte. The proposed method offers a robust decomposition of the electrode impedance model and can be seamlessly integrated into clinical practice using standard software. It provides features for applications such as estimating electrode array insertion depth, assessing residual hearing, and monitoring tissue responses, thus supporting clinical decision-making and further research.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109348"},"PeriodicalIF":2.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-19DOI: 10.1016/j.heares.2025.109372
Fan Wu , Shan Xu , Hongguo Su, Khujista Haque, Qiaojun Fang, Su-Hua Sha
{"title":"Prevention of aminoglycoside-induced outer hair cell loss by silencing CaMKKβ in an acute mouse model","authors":"Fan Wu , Shan Xu , Hongguo Su, Khujista Haque, Qiaojun Fang, Su-Hua Sha","doi":"10.1016/j.heares.2025.109372","DOIUrl":"10.1016/j.heares.2025.109372","url":null,"abstract":"<div><div>The use of ototoxic drugs remains a common cause of acquired hearing loss worldwide. Among them, aminoglycoside antibiotics are still widely used in clinical practice. Although the pathological mechanisms underlying aminoglycoside-induced hearing loss have been extensively studied, no clinically effective pharmacological treatment is currently available to prevent such ototoxicity. Our previous study demonstrated that calcium overload and activation of the Ca²⁺/calmodulin-dependent protein kinase kinase (CaMKK) pathway play a critical role in noise-induced hearing loss. In this study, we assessed the activation of CaMKKβ in an acute ototoxicity model induced by kanamycin plus furosemide (KM + FU). We silenced CaMKKβ using small interfering RNA in young adult CBA/J mice and AAV-mediated shRNA in FVB/NJ mice to determine whether reduction of CaMKKβ in hair cells could prevent KM + FU-induced outer hair cell loss and hearing loss. Remarkably, both silencing approaches provided significant prevention of KM + FU-induced outer hair cell loss. Moreover, RNA interference targeting CaMKKβ did not alter the permeability of the stria vascularis or the uptake of kanamycin through mechanoelectrical transduction channels in hair cells. These findings suggest that CaMKKβ is a promising therapeutic target for prevention of aminoglycoside-induced hearing loss in acute model.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109372"},"PeriodicalIF":2.5,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-18DOI: 10.1016/j.heares.2025.109370
Qianling Su , Ruichun Chen , Jingqun Mo, Meijuan Li, Jiazhang Wei, Jingjin Weng, Shenhong Qu, Min Li
{"title":"Application progress of Tubomanometry (TMM) in Eustachian tube function evaluation: A review","authors":"Qianling Su , Ruichun Chen , Jingqun Mo, Meijuan Li, Jiazhang Wei, Jingjin Weng, Shenhong Qu, Min Li","doi":"10.1016/j.heares.2025.109370","DOIUrl":"10.1016/j.heares.2025.109370","url":null,"abstract":"<div><div>The Eustachian tube (ET) plays a pivotal role in preserving normal auditory function by regulating middle ear (ME) air pressure, facilitating the drainage of secretions from the tympanic cavity, and preventing retrograde infection by pathogens originating from the nasopharynx. Evaluation of ET function is of paramount importance in the diagnosis and treatment of otologic disorders, as it is closely related to the development, management, and prognosis of ME conditions. Currently, the widely utilized ET function tests exhibit distinct advantages and limitations, along with specific indications for applications. These tests cannot serve as a standalone diagnostic criterion for Eustachian Tube Dysfunction (ETD). Tubomanometry (TMM), a relatively simple and non-invasive semi-objective assessment of ET function, holds promise as a robust tool for diagnosing functional abnormalities in the ME. This article introduces the fundamental principles underlying TMM technology and reviews its clinical applications.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"466 ","pages":"Article 109370"},"PeriodicalIF":2.5,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-16DOI: 10.1016/j.heares.2025.109371
Linhan Huang , Min Chen , Shuwen Fan , Nafisa Tursun , Xueying He , Wen Li , Shufeng Li
{"title":"Machine learning identification of tinnitus-related features in auditory peripheral spontaneous activity in a guinea pig noise-induced tinnitus model","authors":"Linhan Huang , Min Chen , Shuwen Fan , Nafisa Tursun , Xueying He , Wen Li , Shufeng Li","doi":"10.1016/j.heares.2025.109371","DOIUrl":"10.1016/j.heares.2025.109371","url":null,"abstract":"<div><h3>Objectives</h3><div>Tinnitus affects millions globally, yet its clinical assessment relies on subjective reports, limiting diagnostic accuracy and treatment development. This study aimed to identify objective, tinnitus-related features within ensemble spontaneous activity (ESA) recorded from the cochlear surface in a guinea pig model and to evaluate their reversibility using extracochlear electrical stimulation (EES) and machine learning.</div></div><div><h3>Design</h3><div>ESA was recorded from four groups: normal controls, noise-exposed animals with tinnitus, noise-exposed animals without tinnitus, and tinnitus animals after EES. Spectral features—central frequency, bandwidth, skewness, and kurtosis—were extracted using Fast-Fourier Transform and sliding window analysis. Behavioral tinnitus was assessed using the gap-prepulse inhibition of the acoustic startle reflex (GPIAS). Five machine learning models were trained to classify tinnitus status based on EES-reversible spectral features, with SHAP analysis used to identify key predictors.</div></div><div><h3>Results</h3><div>Tinnitus-related spectral alterations were observed in frequency bands associated with the exposure noise and its harmonic/subharmonic ranges. These changes were reversed by EES, coinciding with behavioral improvement in GPIAS. The support vector machine achieved the highest classification performance (AUC = 0.962). SHAP analysis identified central frequency (1400–1600 Hz) and skewness (8000–9000 Hz; 16,000–17,000 Hz) as the most informative features.</div></div><div><h3>Conclusions</h3><div>These findings suggest that specific ESA spectral features serve as objective and reversible biomarkers of tinnitus in a guinea pig model, offering potential for translation to clinical diagnostics and therapeutic monitoring.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"465 ","pages":"Article 109371"},"PeriodicalIF":2.5,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hearing ResearchPub Date : 2025-07-14DOI: 10.1016/j.heares.2025.109369
Weitao Jiang , Feng Bai , Guanrun Wang , Xiong Liu , Bin Peng , Xingzhi Xu , Guohui Nie , Wei-Guo Zhu , Bing Hu , Xin-Hai Pei
{"title":"BRCA1 deficiency promotes DNA damage in cochlear hair cells with activation of ATM-p53 pathway independent of CHK2","authors":"Weitao Jiang , Feng Bai , Guanrun Wang , Xiong Liu , Bin Peng , Xingzhi Xu , Guohui Nie , Wei-Guo Zhu , Bing Hu , Xin-Hai Pei","doi":"10.1016/j.heares.2025.109369","DOIUrl":"10.1016/j.heares.2025.109369","url":null,"abstract":"<div><div>Platinum-based chemotherapy drugs, including cisplatin (CDDP), are known to cause irreversible hearing loss. We recently discovered that BRCA1 facilitates the repair of CDDP-induced DNA double-strand breaks (DSBs) in cochlear hair cells (HCs) and prevents hearing loss. However, the checkpoint pathways activated in response to DSBs in HCs, and the mechanisms by which Brca1 regulates these pathways, remain unclear. In this study, we demonstrate that CDDP induces significant DSBs in outer HCs (OHCs), accompanied by phosphorylation of ATM, CHK2, and p53 at serine‑15 (S15) and S20, leading to apoptosis. In contrast, CDDP induces fewer DSBs in inner HCs (IHCs), with phosphorylation of ATM and p53 at S20, but not CHK2, promoting cell survival. Brca1 deficiency further increases phosphorylation of ATM and p53 at S15 in CDDP-treated OHCs. In response to CDDP, phosphorylation of CHK2 is not detected, but phosphorylation of p53 at S20 is enhanced in Brca1-deficient OHCs, whereas, phosphorylation of p53 at S20 is significantly increased in both Brca1-deficient and proficient IHCs. The expression patterns of phosphorylated ATM, CHK2, and p53 in response to CDDP in cultured explants and cell lines differ markedly from those observed in Brca1-deficient and proficient mice in vivo. These findings suggest that CDDP induces extensive DSBs in OHCs, activating the ATM-CHK2-p53 pathway to promote cell death, while Brca1 deficiency exacerbates CDDP-induced DSBs and activates ATM-p53 signaling independent of CHK2, accelerating OHC loss. Additionally, these results demonstrate that CDDP induces modest DSBs in IHCs with activation of the ATM-p53 pathway, independent of CHK2 and BRCA1, leading to cell survival.</div></div>","PeriodicalId":12881,"journal":{"name":"Hearing Research","volume":"465 ","pages":"Article 109369"},"PeriodicalIF":2.5,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}