PLOS One · Sep 2026
Shomaila Mehmood, Pankaj Bhatia, Samson Jamesdaniel
Abstract
Objective Cisplatin, a life-saving chemotherapeutic drug, causes ototoxicity. Although sodium thiosulfate is used to prevent ototoxicity in pediatric patients, no other intervention has been approved for clinical use against cisplatin-induced hearing loss. Hence, there is an urgent need to identify drugs that prevent cisplatin ototoxicity. Methods CBA/J mice were treated with cisplatin (3 mg/kg, i.p., daily for 5 days), and MnTBAP (10 mg/kg, i.p., daily for 8 days) was used to inhibit cisplatin-induced ototoxicity. Auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) were recorded before and after treatment to assess hearing loss, while immunohistochemistry with anti-Myosin-VIIa was conducted to examine hair cell loss, with phalloidin to examine spiral ganglion neuron (SGN) loss, and with anti-nitrotyrosine to assess nitrotyrosine levels. Results Cisplatin treatment elevated the nitrotyrosine levels in hair cells and SGNs and increased the loss of these cells in the middle and basal cochlear regions. A negative correlation was observed between cisplatin-induced changes in the hair cell count or SGN density and nitrotyrosine levels. Cisplatin treatment elevated the hearing thresholds, as indicated by the ABRs, and lowered the DPOAE amplitudes, suggesting cisplatin-induced hearing loss. However, MnTBAP cotreatment prevented the cisplatin-induced changes in hearing sensitivity and reversed the morphological changes. Conclusion The otoprotection observed with MnTBAP cotreatment along with the attenuation of cisplatin-induced increase in nitrotyrosine levels in the cochlea indicates its potential as an inhibitor of cochlear nitrative stress and its utility in mitigating cisplatin-induced ototoxicity.
CNS Neuroscience & Therapeutics · Sep 2026
Minhui Xia, Tianshi Sun, Wenyu Hou, … Mingyu Xia
Abstract
Background Hearing loss primarily results from irreversible cochlear hair cell (HC) damage caused by factors such as noise, aging, genetics, and ototoxic drugs including cisplatin. Currently, there are no effective clinical otoprotective agents available. The natural compound paeonol, derived from Paeonia suffruticosa, exhibits potential anti‐inflammatory and antioxidant properties, positioning it as a promising therapeutic candidate given the central roles of oxidative stress and inflammation in hearing loss pathogenesis. Methods and Results Using mouse cochlear explant cultures, we demonstrated that paeonol protects against cisplatin‐induced HC damage in a concentration‐dependent manner and reduces the accumulation of MitoSOX, TNF‐α, and IL‐6. In vivo, paeonol administration not only prevented cisplatin‐induced HC loss and inner HC synaptic degeneration but also conferred protection against noise‐induced HC damage and hearing loss, demonstrating broad otoprotective efficacy. Mechanistically, RNA‐seq analysis revealed that paeonol exerts its protective effect partly by preventing ribosome biogenesis dysfunction, thereby ensuring normal protein synthesis in HCs. Conclusions Together, our work demonstrates the efficacy of paeonol across multiple models and reveals a potential protective mechanism, paving the way for its development as a much‐needed otoprotective drug.
iScience · Sep 2026
Yoko Nakano, Elizabeth C. Driver, Ning Hu, … Botond Bánfi
Abstract
The transcription factor ATOH1 is a master regulator of mechanosensory hair-cell (HC) development in the ear. Here, we report that its target gene Casz1 regulates the maturation of outer HCs (OHCs). Genetic deletion of Casz1 during (but not after) cochlear development in the mouse caused: hearing loss; disorganization of mechanosensory stereocilia bundles in OHCs; reduced F-actin density in OHC cuticular plates; progressive OHC loss; and mild morphological alterations in inner HCs. This deletion also altered gene expression, delaying downregulation of genes expressed in immature OHCs, including the actin regulator-encoding gene Coro2a, and accelerating upregulation of genes expressed in mature OHCs. Deleting Coro2a in Casz1 mutant mice restored F-actin density in cuticular plates but increased stereocilia bundle disorganization and hearing thresholds, revealing that CORO2A provides an overall beneficial effect. Our data indicate that CASZ1 regulates transcriptional and morphological maturation of OHCs, and that CASZ1 in maturing HCs is necessary for hearing.
Aging Cell · Aug 2026
Piece Yen, Adam J. Carlton, Andrew O'Connor, … Jing‐Yi Jeng
Abstract
Mammalian cochlear hair cells convert acoustic stimuli into electrical signals, which are relayed to the central auditory pathway via auditory neurons. Progressive loss of hair cells and their synapses is a characteristic of age‐related hearing loss (ARHL), but the underlying mechanisms remain poorly understood. In this study, we tested the hypothesis that hair cell physiological properties change with age in CBA/CaJ mice, a strain known for its slow ARHL progression. We found that hair cell size began to decrease from 10 months of age, well before detectable increase in hearing thresholds from auditory brainstem responses. This structural change was associated with a significant decrease in the size of the basolateral membrane current, in particular that carried by the large conductance calcium‐activated potassium (BK) channel currents ( I K,f ) in the apical inner hair cells (IHCs). However, the size of the mechanoelectrical transducer (MET) current measured in the IHCs remained unaffected at least up to 22 months of age. Our results provide clear evidence of an early change in the physiological properties of apical IHCs with age, which precedes measurable hearing loss, suggesting that these cellular deficits might define a distinct pathological route in the CBA/CaJ mice.
Experimental & Molecular Medicine · Aug 2026
Mingxuan Wu, Gaogan Jia, Yanyan Jia, … Wenyan Li
Abstract
Understanding the molecular basis of hair cell function is essential for elucidating inner ear physiology and developing therapies for auditory–vestibular disorders. Here, we identify acyl-CoA binding domain-containing 7 ( Acbd7 ) as a hair cell-specific gene critical for sensory maintenance. Single-cell transcriptomics of mouse cochlear organoids revealed Acbd7 as a top hair cell-enriched transcript, with its spatiotemporal expression confirmed from embryonic development through adulthood in both auditory and vestibular hair cells. Acbd7 ‑deficient mice exhibited pronounced hair cell degeneration, characterized by synaptic defects and diminished calcium currents in inner hair cells and loss of outer hair cells. Transcriptomic and proteomic analyses linked Acbd7 to the regulation of Ca 2+ signaling and fatty acid metabolism pathways. Our findings establish Acbd7 as a critical regulator of Ca 2+ homeostasis and functional integrity in hair cells, thereby elucidating a key mechanism by which a fatty acid metabolism factor sustains hair cell function and providing potential therapeutic targets for inner ear disorders.
Frontiers in Immunology · Aug 2026
Shelby A. Payne, Haley R. Anderson, Isaac M. Brown, … Hainan Lang
Abstract
The auditory nerve (AN) glial transition zone (GTZ), where myelination shifts from Schwann cells in the peripheral AN to oligodendrocytes in the central AN, is a unique biological niche housed within the cochlear modiolus. Although age-related hearing loss (ARHL) is associated with AN degeneration, the neuroimmune mechanisms contributing to age-related myelin pathology and altered immune cell function remain poorly defined. We hypothesized that the AN GTZ is especially vulnerable to age-related immune activity which may contribute to AN degeneration and myelin pathology. Using an ARHL mouse model, we combined large-field light sheet microscopy of tissue-cleared mouse temporal bones, three-dimensional high-resolution imaging, and quantitative immunohistochemistry to evaluate the AN GTZ. RNA-sequencing was used to evaluate age-related changes in gene expression of the whole AN. Human temporal bones were also examined to evaluate the AN and its macrophages/microglia. RNA-sequencing revealed age-associated enrichment of neuroinflammation and myelin degeneration-related pathways. Aging was associated with an increase in Iba1 + macrophages/microglia throughout the AN, with prominent accumulation at the AN GTZ. The aged AN GTZ contained Iba1 + subpopulations expressing CD206, Gal3, CD163, and Lamp1, suggesting enhanced phagocytic activity and altered activation state at the AN GTZ. CD68 + cells were also increased at the AN GTZ, as well as the central AN, with aging. Macrophages/microglia contained significantly more internalized myelin debris across all regions of the AN with aging, including myelin localized within Lamp1 + lysosomes of Iba1 + cells. More importantly, normal-appearing myelin was frequently observed within macrophages/microglia at the AN GTZ, but not in the peripheral or central regions of the AN. Myelin debris within Iba1 + cells was also found in the human AN, consistent with our findings in mouse. Together, these findings identify the AN GTZ as a unique microenvironment with age-related alterations in phagocytic activity and immune activation. The immune cell heterogeneity and enhanced myelin phagocytosis observed in the aging AN emphasize the importance of defining how distinct macrophage/microglia populations contribute to AN degeneration and ARHL.
Journal of Pineal Research · Jun 2026
Siyu Qiu, Shiyi Cai, Rong Xie, … Yingzi He
Abstract
Hearing impairment is attributed to factors such as age, genetic predisposition, and environmental influences, among which environmental factors are considered modifiable. Among various environmental factors, the role of poor lifestyle habits is particularly critical, yet the specific mechanisms by which they contribute to hearing damage remain unclear. This study reveals that dysregulated hormone levels due to disrupted light exposure may significantly increase susceptibility to sensorineural hearing loss. In mice, circadian rhythm disruption was found to reduce melatonin and elevate serotonin levels in the inner ear, thereby increasing vulnerability to cisplatin‐induced ototoxicity. In both in vivo and in vitro cisplatin‐treatment models, we showed that combined treatment with melatonin protected hearing, reduced inner ear cell death, and preserved synaptic connections, whereas serotonin co‐administration exacerbated the damage. Using small molecule–protein interaction prediction, we identified NOS3 as a potential target of both melatonin and serotonin, through which they appear to regulate the NO signaling pathway and influence hair cell ferroptosis. Finally, exogenous supplementation of NOS3 in cochlear tissues effectively mitigated cisplatin‐induced hair cell damage, even under conditions of circadian rhythm disruption. These findings indicate that the melatonin/serotonin balance modulates susceptibility to sensorineural hearing loss via the NOS3–NO signaling pathway.
Scientific Reports · May 2026
Pankaj Bhatia, Katherine Roth, Zhao Yang, … Samson Jamesdaniel
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants linked to adverse health effects. Recent epidemiological data suggest an association between PFAS exposure and hearing loss, but underlying mechanisms remain unclear. This study examined PFAS-induced auditory dysfunction in mice exposed to a mixture of five PFAS compounds (2 mg/L each) in drinking water for seven weeks. Ldlr-/- mice were used due to their susceptibility to metabolic dysfunction, a risk factor for hearing loss. Auditory brainstem responses (ABR) indicated that PFAS exposure significantly elevated hearing thresholds by 18-33 dB across multiple frequencies. Distortion product otoacoustic emissions (DPOAEs) revealed impaired outer hair cell (OHC) function, and immunohistochemical analysis indicated a 20% OHC loss in the basal turn of the cochlea. In addition, PFAS exposure reduced ABR wave-1 amplitudes, and caused a 50% reduction in spiral ganglion cell density, indicating impaired auditory nerve function. Overall, this study provides the first evidence for PFAS-induced high-frequency hearing loss in mice. The findings further indicated that cochlear OHCs and spiral ganglion neurons are potential targets in PFAS-induced hearing loss. Together, these data suggest that PFAS exposure elicits a multifaceted ototoxic response, affecting both sensory and neural elements of the cochlea.
Scientific Reports · May 2026
Aysegul Gungor Aydin, Pranav Manoj, Faiza Ramadan, … Kasia M. Bieszczad
Abstract
Hearing is the largest modifiable mid-life risk factor for Alzheimer's disease (AD), yet its link to dementia remains unclear. We identified a neurophysiological biomarker of AD risk using the non-invasive, rapidly acquired, and clinically translatable auditory brainstem response (ABR) in normal hearing knock-in rats (Swedish familial AD risk variant to Amyloid precursor protein, AppS; male and female). Human ABRs have been proposed as a biomarker for AD and related dementias. The novel metric reported here is derived from multidimensional parametric feature extraction on the distribution statistics of repeated single-trial ABR traces. We report accurate prediction of genetic risk for AD risk in young and aged rats: AppS separate clearly from healthy humanized (AppH) in sex- and age-dependent manners. Notably, auditory learning during young adulthood shifted the AppS ABR signature towards a healthy AppH-like state that maintained over time into older age. Altogether the findings support the utility of the ABR to track disease state, progression, and effects of intervention, and point to a central neural generator of auditory dysfunction related to AD risk. ABRs could provide a very early biomarker for detection of AD risk and used to test the synergy of auditory and cognitive functions in human dementia.
International Journal of Molecular Sciences · Apr 2026
Mi-Jung Kim, Robert J. Fuentes, Yingjie Zhou, Jing Zheng
Abstract
Oncomodulin (OCM) is the most abundant Ca2+ buffering protein found in mature outer hair cells (OHCs). Cadherin 23 (CDH23) is a crucial component of the tip-links in hair cell stereocilia. The absence or dysfunction of these two proteins contributes to the early onset of age-related hearing loss (AHL). In this study, we investigated the effects of the Cdh23753G→A mutation on OHC function using new Ocm-knockout (KO) mouse models (Ocmtm1a/tm1a) with or without the Cdh23753G→A mutation. Despite having the same genetic background, Ocm-KO mice carrying the Cdh23753G→A mutation displayed a notable decline in OHC function across all measured frequencies as early as three months of age. In contrast, Ocm-KO mice without the Cdh23753G→A mutation did not exhibit comparable hearing loss until they reached twelve months of age. Additionally, we examined the role of OCM in preserving OHC function under ototoxic stress induced by HPβCD (2-hydroxypropyl-β-cyclodextrin). The distortion product otoacoustic emission data show that the administration of HPβCD resulted in a more pronounced decline in OHC function in Ocm-KO mice compared to wild-type (WT) mice. Time-lapse recording also shows that HPβCD treatment led to greater structural deterioration and more rapid rupture events in OHCs from Ocm-KO mice than in those from WT mice. These findings suggest that the Cdh23753G→A mutation, rather than other potential strain-specific genetic factors associated with AHL, significantly exacerbates the early onset of AHL phenotypes in Ocm-KO mice. Furthermore, our data indicates that the OCM protein in OHCs enhances their ability to withstand ototoxic stimuli.
Cellular and Molecular Neurobiology · Apr 2026
Yige Li, Siyu Qiu, Fang Wang, … Geng-Lin Li
Abstract
The CUGBP Elav-like family 4 (CELF4), an RNA-binding protein, is dynamically expressed in spiral ganglion neurons (SGNs) in the cochlea over development, but how Celf4 is involved in regulating hearing functions is poorly understood. In this study, we generated a Celf4 ± mouse line and examined changes in the first two synapses along the auditory pathways. Firstly, we found that hearing functions were largely intact in Celf4 ± mice, with exception of reduced amplitude for Wave II of auditory brainstem responses (ABRs) and increased delays for Wave II and IV, both in case of 4 kHz only. Secondly, we found that counts of inner and outer hair cells (IHCs and OHCs) and SGNs remained unchanged in Celf4 ± mice, and that the number and function of ribbon synapses between IHCs and SGNs were comparable between WT and Celf4 ± mice. Lastly, function of the endbulb of Held synapse, formed between auditory nerve fibers (ANFs) of SGNs and bushy cells in the cochlear nucleus, was significantly altered in Celf4 ± mice. Specifically, synaptic vesicle release was subtly reduced, and excitability of bushy cells was significantly dampened, likely due to a hyperpolarized resting membrane potential. Furthermore, we found that spike kinetics was significantly faster in Celf4 ± bushy cells, likely caused by a larger fast-inactivating A-type potassium current (I A ) found in these cells. In conclusion, we found that Celf4 haploinsufficiency altered transmission at the endbulb of Held synapses in the cochlear nucleus in a significant and multifaceted manner, revealing the roles of Celf4 in regulating hearing functions. Graphical Abstract Title: Schematic representation of the experimental approach and major findings. Legend: In mice with Celf4 haploinsufficiency, we found that while function at hair cell ribbon synapses was largely preserved, transmission at the endbulb of Held synapse was significantly altered, including subtly reduced release of synaptic vesicles from the endbulb, dampened excitability in bushy cells, and accelerated spike kinetics caused by enhanced voltage-gated K + current.
bioRxiv · Apr 2026
Mohammed Al-Yaari, Jianing Li, Christian Keine, … Samuel M. Young
Abstract
Activity-dependent modulation of presynaptic voltage-gated Ca 2+ channels (Ca V 2) regulates Ca 2+ influx to control neuronal circuit output. Although Ca V 2.1 can undergo robust Ca 2+ dependent facilitation (CDF), whether it occurs in native central nervous system neuronal circuits is disputed. Accurate auditory information processing requires precise and reliable synaptic transmission at high activity rates in the auditory brainstem. To determine if Ca V 2.1 CDF is a key regulator of high-fidelity synaptic transmission, we expressed Ca V 2.1 splice variants capable (Ca V 2.1 37a) or incapable (Ca V 2.1 37b) of CDF at the calyx of Held presynaptic terminal in the auditory brainstem. We found no difference in basal Ca V 2.1 currents or synaptic transmission. However, Ca V 2.1 37b terminals lacked CDF, synaptic facilitation and had a decreased reliability and precision of postsynaptic action-potential firing. Additionally, the Wave III amplitude of the auditory brainstem responses was reduced. We propose that Ca V 2.1 CDF is essential for accurate auditory information processing.
Communications Biology · Apr 2026
Jing Pan, Kaiye Wang, Jiaxi Qu, … Hongzheng Zhang
Abstract
Cisplatin is widely used in oncology yet causes dose-limiting, irreversible hearing loss through cochlear hair-cell injury. Although mitochondrial dysfunction is central to this ototoxicity, how the outer mitochondrial membrane (OMM) fails in hair cells remains unclear. We identify BAX-associated mitochondrial membrane rupture and abnormal permeabilization as key drivers. In HEI-OC1 cells and murine cochlear explants, super-resolution and transmission electron microscopy revealed cisplatin-induced BAX translocation and oligomerization on the OMM, forming ring-like assemblies with ultrastructural damage (rupture, herniation, fragmentation). Subcellular fractionation and functional assays demonstrated consequent mitochondrial outer membrane permeabilization, cytochrome c release, loss of membrane potential, and accumulation of reactive oxygen species (ROS). Pharmacologic inhibition of BAX oligomerization with BAX inhibitor peptide V5 (BipV5) preserved mitochondrial integrity, reduced ROS, and limited hair-cell loss in vitro. In vivo, repeated transtympanic delivery of BipV5 conferred sustained functional protection and reduced outer hair cell loss. These findings establish a structural mechanism linking mitochondrial membrane rupture to redox imbalance and apoptosis in cochlear hair cells and nominate BAX oligomerization as a drug-targetable node for preventing cisplatin ototoxicity without compromising anticancer therapy.
Cell Death Discovery · Apr 2026
Wenli Hao, Song Gao, Suhan Guo, … Cheng Cheng
Abstract
Lipid metabolism is an important biological process that maintains the dynamic balance of several key functions, such as intracellular energy metabolism, signal transduction, and membrane remodeling. However, the role of lipid metabolism in auditory function and the underlying mechanisms remain unclear. Our results reveal that the neomycin exposure disrupts lipid metabolism in auditory system. We find that neomycin-induced hair cells (HC) damage leads to abnormal lipid droplets (LD) accumulation. Further research reveals that decreased YAP expression is a key factor that contributes to abnormal LD accumulation. In both in vivo and in vitro studies, Yap overexpression reduces abnormal LD accumulation and mitigated HC damage. To further investigate its downstream mechanisms, we perform a cross-analysis of Yap -related and lipid metabolism–related genes, identifying that Cox2 is a key downstream target of Yap that contributes to LD accumulation and HC damage. Our work provides clear evidence for the role of lipid metabolism in neomycin-induced hearing loss and elucidates underlying mechanism of Yap/Cox2 pathway. These findings provide new perspectives and avenues for the clinical treatment of sensorineural hearing loss.
Cell Research · Apr 2026
Huihui Liu, Shangfeng Liao, Xiaowei Li, … Hao Wu
Abstract
The molecular and cellular mechanisms underlying the function of the cochlear nucleus (CN) remain to be fully elucidated. Using single-nucleus RNA sequencing and single-cell spatial transcriptome analyses, we generated a comprehensive cell type atlas of the mouse CN, identified molecularly defined CN subregions, and quantified changes in gene expression and the spatial organization of CN cells in normal mice during postnatal development and in mutant mice with congenital hearing loss. We further identified a subtype of bushy cells expressing the osteopontin-encoding gene Spp1 as the primary CN cell type that exhibited hearing loss-induced alteration of gene expression. Among the highly affected genes in bushy cells, deletion of the auditory input-regulated gene Spp1 affected CN processing of auditory signals in mice. These results provide the most comprehensive cellular and molecular database to date for understanding auditory processing within the CN and identifying potential therapeutic targets for hearing restoration at the CN level.
Cell Reports Medicine · Apr 2026
Liyan Zhang, Yicheng Lu, Xianmin Wu, … Fangzhi Tan
Abstract
Approximately 50% of hereditary deafness cases and most age-related hearing loss result from cochlear hair cell dysfunction. Adeno-associated virus (AAV)-mediated gene therapy offers a promising strategy for hearing restoration. However, the cochlea's complex cellular composition poses a significant challenge for targeted gene delivery into hair cells. Here, we establish a cross-species screening platform for cochlear AAV tools, applicable from rodents to large animals. Using this platform, we identify human promoters that specifically target inner hair cells, outer hair cells, or all hair cells in mice. The hair cell-specific coProB2 promoter is further validated in Bama miniature pigs and cynomolgus monkeys, achieving specific transgene expression in hair cells without auditory toxicity. Importantly, coProB2-driven gene therapies in DFNB79 and DFNB9 mouse models restore auditory function to near wild-type levels. Thus, this study establishes a cross-species-compatible, hair cell-specific AAV system, providing a versatile toolbox for cochlear hair cell gene therapy.
eBioMedicine · Apr 2026
Yun Xiao, Lei Chen, Yuechen Han, … Haibo Wang
Abstract
Background: Genetic diagnosis plays a critical role in enhancing the identification and clinical management of pediatric hearing loss, ultimately improving both physiological outcomes and social-emotional development. As one of the most prevalent sensory disorders characterized by substantial genetic heterogeneity, hearing loss requires the implementation of efficient diagnostic approaches to inform targeted clinical interventions and personalized care strategies. Methods: Here, we recruited 3353 Han Chinese children with nonsyndromic hearing loss, including 598 multiplex cases with family history. We employed SNPscan, targeted panel sequencing (TPS), and whole-exome sequencing (WES) to delineate the mutation landscape. Findings: Utilizing a tiered genomic testing strategy, we performed SNPscan for all 3353 participants, TPS for 675 cases, and WES for 204 multiplex cases. We achieved an overall diagnostic yield of 48.3% (1620/3353) in this cohort. Our analysis identified 87 previously unreported variants across 24 genes, including a de novo FOXI1 mutation (c.479_481del) linked to Mondini malformation and enlarged vestibular aqueduct, validated through knock-in mouse models. Additionally, we discovered NEU4 as a candidate gene related to hearing loss, with knockout mice and cellular models demonstrating its role in auditory dysfunction via disrupted neuraminidase activity and axonal development. These findings enrich the spectrum of deafness-related genes and provide a new theoretical foundation for diagnosing hearing loss. Interpretation: This study not only expands the genetic spectrum of hearing loss but also underscores the clinical utility of advanced sequencing in guiding precision therapies and early syndromic surveillance. This study offers a detailed characterization of the genetic landscape of pathogenic variants associated with hearing loss in the Han Chinese population, which will contribute to the design of a cost-effective genetic screening scheme, and also provides valuable insights that contribute to the global understanding of the genetics of hearing loss. Funding: This work was supported by the Key Program of National Natural Science Foundation of China, the National Key Research and Development Program of China, the National Natural Science Foundation of China and the Major Fundamental Research Program of the Natural Science Foundation of Shandong Province, China.
Hearing Research · Apr 2026
J.A. Mondul, C.A. Mackey, A.N. Conner, … T.A. Hackett
Abstract
Noise exposures causing transient hearing loss were previously considered benign. However, recent work has revealed that temporary noise-induced threshold shifts may be associated with long-lasting cochlear histopathology. One such effect is cochlear synaptopathy, i.e. changes to the afferent synapse between inner hair cells and auditory nerve fibers. Noise-induced synaptopathy has been extensively characterized in several rodent models, and temporal bone studies suggest similar age-related changes in humans. However, it remains unclear how noise-induced temporary threshold shifts affect cochlear structures in humans and nonhuman primates, which show greater resistance to noise exposure than other animals. Additionally, the long-term sequelae of temporary threshold shifts are largely unknown. Here, we characterized the effects of a noise exposure causing temporary threshold shifts on cochlear histopathology in macaque monkeys at long post-exposure survival times. Overall, cochlear histopathology was variable across subjects, similar to the variable susceptibility observed in humans. At 2 and 10 months post-exposure, macaques had no significant loss of hair cells, inner hair cell synapses, or cholinergic efferent innervation. However, both inner and outer hair cell ribbons showed significant enlargement. Together, these findings provide insight into the cochlear effects of single-exposure temporary threshold shifts in nonhuman primates.
Scientific Reports · Feb 2026
Abhijeeth Erra, Cayla M. Miller, Jeffrey Chen, … Uri Manor
Abstract
Hearing loss is a pervasive global health challenge with profound impacts on communication, cognitive function, and quality of life. Recent studies have established age-related hearing loss as a significant risk factor for dementia, highlighting the importance of hearing loss research. Auditory brainstem responses (ABRs), which are electrophysiological recordings of acoustically evoked synchronized neural activity from the auditory nerve and brainstem, serve as in vivo correlates for sensory hair cell and synaptic function, hearing sensitivity, and other critical readouts of auditory pathway physiology, making them highly valuable for both basic neuroscience and clinical research. Despite the utility of the ABR, traditional ABR analyses rely heavily on subjective manual interpretation, which may introduce variability and pose challenges for reproducibility across studies. Here, we introduce Auditory Brainstem Response Analyzer (ABRA), a novel suite of open-source ABR analysis tools powered by deep learning, which automates and standardizes ABR waveform analysis. ABRA employs convolutional neural networks trained on diverse datasets collected from multiple experimental settings, achieving rapid and unbiased extraction of key ABR metrics, including peak amplitude, latency, and auditory threshold estimates. We demonstrate that ABRA’s deep learning models provide performance comparable to expert human annotators while dramatically reducing analysis time and enhancing reproducibility across datasets from different laboratories. By bridging hearing research, sensory neuroscience, and advanced computational techniques, ABRA facilitates broader interdisciplinary insights into auditory function. An online version of the tool is available for use at no cost at https://abra.ucsd.edu .
Science Advances · Jan 2026
Dana K. Mitchell, Kylee Brewster, Li Jiang, … D. Wade Clapp
Abstract
NF2 (neurofibromatosis type 2)–related schwannomatosis (NF2-SWN) is a cancer predisposition syndrome characterized by the development of bilateral vestibular (VS) and spinal schwannomas. While benign, these tumors can cause substantial morbidity, and effective pharmacological treatments remain limited. Here, we demonstrate that genetic ablation of focal adhesion kinase ( Fak/Ptk2 ) impairs tumor formation and preserves hearing in a murine model of NF2. Mechanistically, we show that Fak deletion decreases macrophage infiltration, attenuates nucleotide-binding oligomerization domain–containing protein 2–, leucine rich repeats (LRR)- and pyrin domain–containing protein 3 inflammasome activation, and suppresses the hepatocyte growth factor–MET axis. Pharmacological inhibition of FAK with single agent VS-4718 did not significantly reduce macroscopic tumor volume; however, its use in combination with the mitogen-activated protein kinase kinase (MEK) inhibitor selumetinib resulted in both a significant reduction in tumor volume and the preservation of dorsal root ganglion architecture. Our findings establish a critical role for FAK in schwannoma development and provide rationale for evaluation of combination FAK plus MEK inhibition in future clinical trials for NF2-associated SWN.