Jaro-Journal of the Association for Research in Otolaryngology最新文献

{"title":"Age-Related Decline in Neural Phase-Locking to Envelope and Temporal Fine Structure Revealed by Frequency Following Responses: A Potential Signature of Cochlear Synaptopathy Impairing Speech Intelligibility.","authors":"Emmanuel Ponsot, Pauline Devolder, Ingeborg Dhooge, Sarah Verhulst","doi":"10.1007/s10162-025-00985-2","DOIUrl":"10.1007/s10162-025-00985-2","url":null,"abstract":"<p><strong>Purpose: </strong>Assessing the contribution of cochlear synaptopathy (CS) to the variability in speech-in-noise intelligibility among individuals remains a challenge. While several studies have proposed biomarkers for CS based on neural phase-locking to the temporal envelope (ENV), fewer have investigated how CS affects the coding of temporal fine structure (TFS), despite its crucial role in speech-in-noise perception. In this study, we specifically examined whether TFS-based markers of CS could be derived from electrophysiological responses and psychophysical detection thresholds of spectral modulation (SM) in a complex tone, which serves as a parametric model of speech.</p><p><strong>Methods: </strong>We employed an integrated approach, combining psychophysical testing with frequency-following response (FFR) measurements in three groups of participants: young normal-hearing (n = 15, 12 females, age 21 ± 1); older normal-hearing (n = 16, 11 females, age 47 ± 6); and older hearing-impaired (n = 14, 8 females, age 52 ± 6). We expanded on previous work by assessing phase-locking to both ENV, using a 4-kHz rectangular amplitude-modulated (RAM) tone, and TFS, using a low-frequency (< 1.5 kHz) SM complex tone.</p><p><strong>Results: </strong>Overall, FFR results showed significant reductions in neural phase-locking to both ENV and TFS components with age and hearing loss. Specifically, the strength of TFS-related FFRs, particularly the component corresponding to the harmonic closest to the peak of the spectral envelope (~ 500 Hz), was negatively correlated with age, even after adjusting for audiometric thresholds. This TFS marker also correlated with ENV-related FFRs derived from the RAM tone, suggesting a shared decline in phase-locking capacity across low and high cochlear frequencies. Computational simulations of the auditory periphery indicated that the observed FFR strength reduction with age is consistent with approximately 50% loss of auditory nerve fibers, aligning with histopathological data. However, the TFS-based FFR marker did not account for variability in speech intelligibility observed in the same participants. Psychophysical measurements showed no age-related effects and were unrelated to the TFS-based FFR marker, highlighting the need for further psychophysical research to establish a behavioral counterpart.</p><p><strong>Conclusion: </strong>Altogether, our results demonstrate that FFRs to vowel-like stimuli can serve as a complementary electrophysiological marker for assessing neural coding fidelity to stimulus TFS. This approach could provide a valuable tool for better understanding the impact of CS on an important coding dimension for speech-in-noise perception.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"249-270"},"PeriodicalIF":2.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12133675/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144000425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Myosin Regulatory Light Chain and Myosin Light Chain Kinase on the Physiological Function of Inner Ear Hair Cells.","authors":"Ryohei Oya, Kwang Min Woo, Brian Fabella, R G Alonso, Paloma Bravo, A J Hudspeth","doi":"10.1007/s10162-025-00986-1","DOIUrl":"10.1007/s10162-025-00986-1","url":null,"abstract":"<p><strong>Purpose: </strong>In the receptor organs of the inner ear, hair cells detect mechanical stimuli such as sounds and accelerations by deflection of their hair bundles. Myosin regulatory light chain (RLC) and non-muscle myosin II (NM2) are expressed at the apical surfaces of hair cells, and NM2 and the phosphorylation of RLC by myosin light chain kinase (MLCK) have earlier been shown to regulate the shapes of hair cells' apical surfaces in rodents. The aim of our study was to elucidate the function of myosin molecules on hair cell physiology.</p><p><strong>Methods: </strong>We investigated the expression of NM2 and RLC in the bullfrog's saccule by immunostaining. Using NM2 and MLCK inhibitors, we measured the stiffness, spontaneous oscillation, and resting open probability of frog hair bundles. Six to ten saccules from pleural animals were used in each experiment. In addition, we recorded auditory brainstem responses in ten mice after transtympanic injection of an MLCK inhibitor.</p><p><strong>Results: </strong>We confirmed the expression of NM2A/B and MYL9 on the apical surfaces of hair cells and of NM2A and MYL12A in hair bundles. We found that NM2 and MLCK inhibitors reduce the stiffness of hair bundles from the bullfrog's saccule. Moreover, MLCK inhibition inhibits the spontaneous oscillation of hair bundles and increases the resting open probability of transduction channels. In addition, MLCK inhibition elevates hearing thresholds in mice.</p><p><strong>Conclusion: </strong>We conclude that NM2 and the phosphorylation of RLC modulate the physiological function of hair cells and thereby help to set the normal operating conditions of hair bundles.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"225-238"},"PeriodicalIF":2.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12133660/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144061021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-Wide Association Study of Age-Related Hearing Loss in CFW Mice Identifies Multiple Genes and Loci, Including Prkag2.","authors":"Oksana Polesskaya, Ely Boussaty, Riyan Cheng, Olivia A Lamonte, Thomas Y Zhou, Eric Du, Thiago Missfeldt Sanches, Khai-Minh Nguyen, Mika Okamoto, Abraham A Palmer, Rick Friedman","doi":"10.1007/s10162-025-00994-1","DOIUrl":"10.1007/s10162-025-00994-1","url":null,"abstract":"<p><strong>Purpose: </strong>Age-related hearing loss (ARHL) is one of the most prevalent conditions affecting the elderly. ARHL is influenced by a combination of environmental and genetic factors; the identification of the genes that confer risk will aid in the prevention and treatment of ARHL. The mouse and human inner ears are functionally and genetically homologous. We used Carworth Farms White (CFW) mice to study the genetic basis of ARHL because they are genetically diverse and exhibit variability in the age of onset and severity of ARHL.</p><p><strong>Methods: </strong>Hearing at a range of frequencies was measured using auditory brainstem response (ABR) thresholds in 946 male and female CFW mice at the age of 1, 6, and 10 months. We genotyped the mice using low-coverage (mean coverage 0.27 ×) whole-genome sequencing (lcWGS) followed by imputation using STITCH. To determine the accuracy of the genotypes, we sequenced 8 samples at > 30 × coverage and used those data to estimate the accuracy of lcWGS genotyping, which was > 99.5%. We performed a genome-wide association study (GWAS) for the ABR thresholds for each frequency at each age, and we also performed a GWAS for age at deafness.</p><p><strong>Results: </strong>We obtained genotypes at 4.18 million single nucleotide polymorphisms (SNP). The SNP heritability for traits ranged from 0 to 42%. GWAS identified 10 significant associations with ARHL that contained potential candidate genes, including Dnah11, Rapgef5, Cpne4, Prkag2, and Nek11. Genetic ablation of Prkag2 caused ARHL at high frequencies, strongly suggesting that Prkag2 is the causal gene for one of the associations.</p><p><strong>Conclusions: </strong>GWAS for ARHL in CFW outbred mice identified genetic risk factors for ARHL, including Prkag2. Our results will help to define novel therapeutic targets for the treatment and prevention of this common disorder.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144121544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frequency Following Responses to Electric Cochlear Stimulation in an Animal Model.","authors":"Matthew L Richardson, Robert P Carlyon, Harrison W Lin, John C Middlebrooks","doi":"10.1007/s10162-025-00992-3","DOIUrl":"https://doi.org/10.1007/s10162-025-00992-3","url":null,"abstract":"<p><strong>Purpose: </strong>Present-day cochlear-implant (CI) users can achieve high levels of speech reception in quiet surroundings. Nevertheless, sensitivity to the temporal pitch of sounds is limited, which contributes to deficits in speech reception amid multiple talkers and in appreciation of musical melodies. Short-term, invasive neurophysiological studies in animals have demonstrated limitations in neural phase locking in the tonotopic range of the auditory pathway that is activated by CIs. It remains an open question, however, whether those neural limitations can account for perceptual deficits in those animal species, let alone in human CI users. For that reason, we have evaluated non-invasive recordings of phase locking from cats chronically implanted with a CI.</p><p><strong>Methods: </strong>Ten deafened cats (eight female) were implanted with an animal version of a clinical CI array. The electrically evoked frequency following response (eFFRs) was recorded from the scalps of sedated animals at ≥ 10 weeks post-implantation. Stimuli consisted of constant-amplitude electrical pulse trains at rates from ~ 40 to 640 pulses per second.</p><p><strong>Results: </strong>Recordings of the eFFR demonstrated robust responses synchronized to electrical pulse trains across all stimulus rates. Analyses of eFFR amplitude and phase transfer functions confirmed that the eFFR, as with its normal-hearing counterpart, originates from multiple subcortical and cortical generators. The slopes of segments of eFFR phase transfer functions revealed stimulus-to-response latencies of generators that dominated the eFFR across restricted ranges of pulse rates. Those rate ranges must coincide with the limits of phase locking by putative generators at successive levels of the auditory neuroaxis and could inform our understanding of the limits to perceptual temporal acuity.</p><p><strong>Conclusion: </strong>The eFFR demonstrated here in an animal model provides a valuable non-invasive measure of temporal processing in electric cochlear stimulation that can be related to ongoing perceptual measures in the same animals and is well-suited to evaluate novel modes of auditory prosthesis for enhancing temporal acuity.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144121535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generational Differences in Audiometric and Self-Reported Hearing and Hearing Aid Use.","authors":"Lauren K Dillard, Lois J Matthews, Judy R Dubno","doi":"10.1007/s10162-025-00993-2","DOIUrl":"https://doi.org/10.1007/s10162-025-00993-2","url":null,"abstract":"<p><strong>Purpose: </strong>Birth cohort differences capture secular trends in population health. We aimed to determine birth cohort differences, defined by generation, in hearing-related outcomes.</p><p><strong>Methods: </strong>Participants were from a community-based cohort study. Generation was classified according to birth year: Greatest (1901-1924), Silent (1925-1945), Baby Boom (1946-1964), Generation X (1965-1980), or Millennial (1981-1996) and Gen Z (1997-2012). Primary outcomes were audiometric hearing loss, defined as a worse ear pure-tone average (PTA) of thresholds at frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB HL, and self-reported hearing difficulty, defined as a score ≥ 6 on the Revised Hearing Handicap Inventory (RHHI). Analyses focused on hearing aid use included only participants with audiometric hearing loss. We used multivariable adjusted logistic regression models to evaluate associations between generation and each outcome. Models were stratified to sex when there was evidence of effect modification.</p><p><strong>Results: </strong>This cross-sectional study included 1554 participants (mean age 63.7 [SD 14.4] years; 56.8% female, 20.0% racial Minority). The prevalence of audiometric hearing loss, self-reported hearing difficulty, and hearing aid use (among participants with audiometric hearing loss) was 48.9%, 48.8%, and 22.0%, respectively. Generation was associated with audiometric hearing loss in the entire sample and males only. Generation was not consistently associated with self-reported hearing difficulty or hearing aid use.</p><p><strong>Conclusion: </strong>More recent generations had lower prevalence of audiometric hearing loss. There were no generational differences in self-reported hearing difficulty or hearing aid use. Secular hearing-related trends can inform accurate projections of the burden of hearing loss and health care utilization.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144103332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model-Based Inference of Electrode Distance and Neuronal Density from Measured Detection Thresholds in Cochlear Implant Listeners.","authors":"David J Perkel, Christopher K Giardina, Joshua H Goldwyn, Julie G Arenberg","doi":"10.1007/s10162-025-00978-1","DOIUrl":"10.1007/s10162-025-00978-1","url":null,"abstract":"<p><strong>Purpose: </strong>Cochlear implants (CI) are a highly successful neural prosthesis that can restore hearing in individuals with sensorineural hearing loss. However, the extent of hearing restoration varies widely. Two major factors likely contribute to poor performance: (1) the distances between electrodes and surviving spiral ganglion neurons and (2) the density of those neurons. Reprogramming the CI at a poor electrode-neuron interface, using focused tripolar stimulation or remapping the electrodes, would benefit from understanding the cause of the poor interface.</p><p><strong>Methods: </strong>We used a cochlear model with simplified geometry and neuronal composition to investigate how the interface affects stimulation thresholds. We then inverted the model to infer electrode distance and neuronal density from monopolar and tripolar threshold values obtained behaviorally. We validated this inverted model for known scenarios of electrode distance and neuronal density. Finally, we assessed the model using data from 18 CI users whose electrode distances were measured from CT imaging.</p><p><strong>Results: </strong>The inverted model accurately inferred electrode distance and neuronal density for known scenarios. It also reliably reproduced behavioral monopolar and tripolar threshold profiles for CI users, with mean prediction errors within 1 dB for 17/18 subjects. Fits of electrode distance were more variable; accuracy depended on the assumed value of temporal bone resistivity. Twelve subjects had minimum distance error (0.31 mm) using low resistivity (70 Ω-cm) while the others had better fits (0.30 mm) with higher resistivity (250 Ω-cm).</p><p><strong>Conclusion: </strong>This inverted model shows promise as a simple, practical tool to better assess and understand the electrode-neuron interface.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"185-201"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996727/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143568925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crosstalk Signaling Between the Epithelial and Non-Epithelial Compartments of the Mouse Inner Ear.","authors":"Abel P David, Sushobhan Biswas, Macey P Soltis, Yasmin Eltawil, Ruiqi Zhou, Sarah A Easow, Alan G Cheng, Stefan Heller, Taha A Jan","doi":"10.1007/s10162-025-00980-7","DOIUrl":"10.1007/s10162-025-00980-7","url":null,"abstract":"<p><strong>Purpose: </strong>The otolith organs of the inner ear consist of the utricle and saccule that detect linear acceleration. These organs rely on mechanosensitive hair cells for transduction of signals to the central nervous system. In the murine utricle, about half of the hair cells are born during the first postnatal week. Here, we wanted to explore the role and interaction of the non-epithelial mesenchymal cells with the sensory epithelium and provide a resource for the auditory neurosciences community.</p><p><strong>Methods: </strong>We utilized full-length Smart-seq2 single-cell RNA sequencing at postnatal days 4 and 6 along with a host of computational methods to infer interactions between the epithelial and non-epithelial compartments of the mouse utricle. We validated these findings using a combination of immunohistochemistry and quantitative multiplex in situ hybridization.</p><p><strong>Results: </strong>We report diverse cell-cell crosstalk among the 12 annotated cell populations (n = 955 cells) in the developing neonatal mouse utricle, including epithelial and non-epithelial cellular signaling. The mesenchymal cells are the dominant signal senders during the postnatal period. Epithelial to mesenchymal signaling, as well as mesenchymal to epithelial signaling, are quantitatively shown through the TGFβ and pleiotrophin pathways.</p><p><strong>Conclusion: </strong>This study highlights the dynamic process of postnatal vestibular organ development that relies not only on epithelial cells, but also on crosstalk between spatial compartments and among different cell groups. We further provide a data-rich resource for the inner ear community.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"127-145"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996748/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143626893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing a Calibration Method to Minimize Variability in Auditory Evoked Potentials.","authors":"Joseph Pinkl, Tao Shen, Jinsai Cheng, John Hawks, Jianxin Bao","doi":"10.1007/s10162-025-00982-5","DOIUrl":"10.1007/s10162-025-00982-5","url":null,"abstract":"<p><strong>Purpose: </strong>To reduce amplitude variability of auditory evoked potentials (AEPs) we developed a circuit that generates an electric calibration pulse (CalPulse) following each evoking sound presentation. We aim to determine if external CalPulse signals can function as a reliable calibration reference for AEP amplitude measurements.</p><p><strong>Methods: </strong>The CalPulse circuit was integrated with an AEP recording montage. The amplitude and morphology of two CalPulse signals (square wave and sine wave) was first assessed in vitro with electrodes submerged in saline. Repeatability of the two signals was then compared in vivo using five (3 male/2 female) 4-month-old CBA/CAJ mice and four unique auditory brainstem response (ABR) configurations. Sine wave CalPulse amplitudes were subsequently used to adjust raw ABR wave-1 amplitudes in a sample of 38 (19 male/19 female) CBA/CaJ mice. Variability in adjusted wave-1 amplitudes was compared with raw amplitudes. Measurements were repeated every month for 4 months (8 to 11 months old) to evaluate its potential as a tool to detect age-related changes in auditory function.</p><p><strong>Results: </strong>Wave quality examinations indicate that both CalPulse signal types are stable in vitro, with the sine wave signal being more repeatable when recorded in vivo. Sine wave CalPulse amplitudes correlated positively with ABR wave-1 amplitudes. Normalizing wave-1 amplitudes with CalPulse measures significantly reduced within-subject variability. Normalized wave-1 amplitudes showed a significant decrease at 10 months of age consistent with age-related cochlear synaptopathy, while uncalibrated wave-1 amplitudes from the same recordings failed to detect this decrease.</p><p><strong>Conclusion: </strong>Our new calibration circuit can be used to improve diagnostic sensitivity of AEP measures.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"111-126"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996742/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Inner Ear and Aging Brain: A Cross-Sectional Study of Vestibular Function and Morphometric Variations in the Entorhinal and Trans-Entorhinal Cortex.","authors":"Claire J Vania, Dominic Padova, J Tilak Ratnanather, Yuri Agrawal","doi":"10.1007/s10162-025-00977-2","DOIUrl":"10.1007/s10162-025-00977-2","url":null,"abstract":"<p><strong>Purpose: </strong>While the vestibular system is crucial for balance, posture, and stable vision, emerging evidence connects vestibular loss in older adults to spatial cognitive deficits. However, the specific neural pathways remain unclear. This study examines morphometric changes in the entorhinal cortex (ERC) and trans-entorhinal cortex (TEC), key regions in the vestibular spatial cognitive network, with vestibular function.</p><p><strong>Methods: </strong>This cross-sectional study used T1-weighted MRI images and vestibular physiological data from 103 Baltimore Longitudinal Study of Aging participants (74 males and 29 females). Vestibular function was assessed through the cervical vestibular-evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), and video head-impulse test (vHIT), examining both categorical presence/absence of responses and continuous measures (cVEMP amplitude, oVEMP amplitude, and VOR gain). Morphometric changes in the ERC and TEC were analyzed by examining surface expansions and contractions relative to average shapes.</p><p><strong>Results: </strong>Reduced saccular function correlated with surface expansion in the left ERC's pro-rhinal, right ERC's intermediate caudal and superior regions, and right TEC's sulcal region. The decreased utricular function was associated with surface contraction in the left lateral TEC, left ERC's anterior sulcal and trans-entorhinal regions, and surface expansion in the lateral region of the left ERC. Reduced canal function showed surface contraction in the right ERC's pro-rhinal and lateral regions and the right TEC's posterior sulcal and trans-entorhinal regions.</p><p><strong>Conclusion: </strong>These findings highlight the intricate link between vestibular function and ERC/TEC morphology, emphasizing their role in spatial and cognitive abilities. Future research will assess if structural changes due to vestibular loss contribute to cognitive deficits in aging and Alzheimer's disease.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"171-184"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996744/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143494852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for the Auditory Nerve Generating Envelope Following Responses When Measured from Eardrum Electrodes.","authors":"Skyler G Jennings, Jessica Chen, Nathan Johansen, Shawn S Goodman","doi":"10.1007/s10162-025-00979-0","DOIUrl":"10.1007/s10162-025-00979-0","url":null,"abstract":"<p><p>Steady-state auditory evoked potentials are useful for studying the human auditory system and diagnosing hearing disorders. Identifying the generators of these potentials is essential for interpretation of data and for determining appropriate clinical and research applications. Here we infer putative generators of a steady-state potential measured from an electrode on the eardrum and compare this potential with the traditional envelope following response (EFR) measured from an electrode on the high forehead (N = 18, 10 female). We hypothesized that responses from the eardrum electrode would be consistent with an auditory nerve (AN) compound action potential (CAP) evoked by each cycle of the stimulus envelope, resulting in a potential we call CAP_ENV. Steady-state potentials were evoked by a 90 dB peSPL, 3000-Hz puretone carrier whose envelope was modulated by a tone sweep with frequencies from 20 to 160 Hz or 80 to 640 Hz. We calculated group delay to infer potential generators. We also compared the empirically measured CAP_ENV with simulated CAP_ENV from a humanized model of AN responses. Response latencies and model simulations support the interpretation that CAP_ENV is generated by the AN rather than hair cell or brainstem generators for all modulation frequencies tested. Conversely, latencies for the traditional EFR were consistent with a shift from cortical to brainstem generators as the modulation frequency increased from 20 to 200 Hz. We propose that CAP_ENV may be a fruitful tool for assessing AN function in humans with suspected AN fiber loss and/or temporal coding disorders.</p>","PeriodicalId":56283,"journal":{"name":"Jaro-Journal of the Association for Research in Otolaryngology","volume":" ","pages":"147-162"},"PeriodicalIF":2.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996730/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143568921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}