scholarly journals DPOAE Intensity Increase at Individual Dominant Frequency after Short-Term Auditory Exposure

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Judit Bakk ◽  
Tamás Karosi ◽  
Tamás József Batta ◽  
István Sziklai
Keyword(s):  
Hair Cells ◽  
Dominant Frequency ◽  
Outer Hair Cells ◽  
Sound Stimulus ◽  
Transient Increase ◽  
Intensity Increase ◽  
Short Term ◽  
Sound Exposure ◽  
Regulatory Processes ◽  
Noise Susceptibility

Previous experiments suggested the possibility of a short-term sound stimulus-evoked and transient increase in DPOAE amplitudes. This phenomenon is possibly due to the complexity of the outer hair cells and their efferent control system and the different time scales of regulatory processes. A total of 100 healthy subjects ranging from 18 to 40 years of age with normal hearing and normal DPOAE values in the range of 781–4000 Hz were recruited in the study. Diagnostic DPOAE measurements were performed after short-term sound exposure. We proposed a 10 sec, 50 dB sound impulse as the most effective stimulus for clinical practice between 40 and 60 sec poststimulus time to detect the aforementioned transient DPOAE increase. We developed a procedure for detection of this transient increase in DPOAE by the application of a short-term sound exposure. The phenomenon was consistent and well detectable. Based on our findings, a new aspect of cochlear adaptation can be established that might be introduced as a routine clinical diagnostic tool. A mathematical model was provided that summarizes various factors that determine electromotility of OHCs and serves as a possible clinical application using this phenomenon for the prediction of individual noise susceptibility.

scholarly journals Slow oscillatory changes of DPOAE magnitude and phase after exposure to intense low-frequency sounds

2019 ◽  
Vol 122 (1) ◽  
pp. 118-131
Author(s):  
Margarete A. Ueberfuhr ◽  
Markus Drexl
Keyword(s):  
Hair Cells ◽  
Otoacoustic Emissions ◽  
Exposure Duration ◽  
Low Frequency ◽  
Outer Hair Cells ◽  
Mongolian Gerbils ◽  
Frequency Sound ◽  
Sound Exposure ◽  
Distortion Product ◽  
Sound Duration

Sensitive sound detection within the mammalian cochlea is performed by hair cells surrounded by cochlear fluids. Maintenance of cochlear fluid homeostasis and tight regulation of intracellular conditions in hair cells are crucial for the auditory transduction process but can be impaired by intense sound stimulation. After a short, intense low-frequency sound, the cochlea shows the previously described “bounce phenomenon,” which manifests itself as slow oscillatory changes of hearing thresholds and otoacoustic emissions. In this study, distortion product otoacoustic emissions (DPOAEs) were recorded after Mongolian gerbils were exposed to intense low-frequency sounds (200 Hz, 100 dB SPL) with different exposure times up to 1 h. After all sound exposure durations, a certain percentage of recordings (up to 80% after 1.5-min-long exposure) showed oscillatory DPOAE changes, similar to the bounce phenomenon in humans. Changes were quite uniform with respect to size and time course, and they were independent from sound exposure duration. Changes showed states of hypo- and hyperactivity with either state preceding the other. The direction of changes was suggested to depend on the static position of the cochlear operating point. As assessed with DPOAEs, no indication for a permanent damage after several or long exposure times was detected. We propose that sensitivity changes occur due to alterations of the mechanoelectrical transduction process of outer hair cells. Those alterations could be induced by different challenged homeostatic processes with slow electromotility of outer hair cells being the most plausible source of the bounce phenomenon. NEW & NOTEWORTHY Low-frequency, high-intensity sound can cause slowly cycling activity changes in the mammalian cochlea. We examined the effect of low-frequency sound duration on the degree of these alterations. We found that cochlear changes showed a stereotypical biphasic pattern independent of sound exposure duration, but the probability that significant changes occurred decreased with increasing sound duration. Despite exposure durations of up to 1 h, no permanent or transient impairments of the cochlea were detected.

Further studies on the ultrastructure of the cochlea

1990 ◽  
Vol 48 (3) ◽  
pp. 440-441
Author(s):  
Zhixian Wang ◽  
Pinjin Zhu ◽  
Jianhe Sun ◽  
Xuezheng Song
Keyword(s):  
Hair Cells ◽  
Military Medicine ◽  
Outer Hair Cells ◽  
Apical Surface ◽  
Epithelial Surface ◽  
Hearing Research ◽  
New Findings ◽  
Fine Structures ◽  
Temporal Bones ◽  
Accurate Observation

Hearing research is important not only for clinical, professional and military medicine, but also for toxicology, gerontology and genetics. Ultrastructure of the cochlea attracts much attention of electron microscopists, (1―3) but the research lags far behind that of the other parts of the organnism. On the basis of careful microdissection, technical improvment and accurate observation, we have got some new findings which have not been reported in the literature.We collected four cochleas from human corpses. Temporal bones dissected 1 h after death and cochleas perfused with fixatives 4 h after death were good enough in terms of preservation of fine structures. SEM:The apical surface of OHCs (Outer hair cells) and DTs (Deiters cells) is narrower than that of IPs (Inner pillar cells). The mosaic configuration of the reticular membrane is not typical. The stereocilia of IHCs (Inner hair cells) are not uniform and some kinocilia could be seen on the OHCs in adults. The epithelial surface of RM (Reissner’s membrane) is not smooth and no mesh could be seen on the mesothelial surface of RM. TEM.

Intraindividual Variability and Stability of Affect and Well-Being

GeroPsych ◽  
2013 ◽  
Vol 26 (3) ◽  
pp. 185-199 ◽  
Author(s):  
Christina Röcke ◽  
Annette Brose
Keyword(s):  
Age Differences ◽  
Well Being ◽  
Subjective Well Being ◽  
Emotional Experiences ◽  
Short Term ◽  
Regulatory Processes ◽  
Functional Implications ◽  
Methodological Approaches ◽  
Underlying Processes

Whereas subjective well-being remains relatively stable across adulthood, emotional experiences show remarkable short-term variability, with younger and older adults differing in both amount and correlates. Repeatedly assessed affect data captures both the dynamics and stability as well as stabilization that may indicate emotion-regulatory processes. The article reviews (1) research approaches to intraindividual affect variability, (2) functional implications of affect variability, and (3) age differences in affect variability. Based on this review, we discuss how the broader literature on emotional aging can be better integrated with theories and concepts of intraindividual affect variability by using appropriate methodological approaches. Finally, we show how a better understanding of affect variability and its underlying processes could contribute to the long-term stabilization of well-being in old age.

Pengaruh sisplatin dosis tinggi terhadap penurunan fungsi sel rambut luar koklea

2013 ◽  
Vol 40 (2) ◽  
Author(s):  
Asti Kristianti ◽  
Teti Madiadipoera ◽  
Bogi Soeseno
Keyword(s):  
Hair Cells ◽  
Malignant Neoplasm ◽  
Otoacoustic Emission ◽  
Outer Hair Cells ◽  
High Dose ◽  
Distortion Product Otoacoustic Emission ◽  
Inclusion Criteria ◽  
Cochlear Hair Cells ◽  
Distortion Product ◽  
Bilateral Sensorineural Hearing Loss

Background: Chemotherapy is worldwide used nowadays, and its toxicity still remain a problemespecially toxicity to the ear (ototoxicity). Cisplatin (cis-diamminedichloroplatinum) is one of themost commonly used chemotherapy and highly potent in treating epithelial malignancies. Ototoxicitycaused by cisplatin is irreversible, progressive, bilateral, sensorineural hearing loss especially on highfrequency (4-8 KHz) accompanied by tinnitus. Purpose: To observe the cochlear outer hair cells damagein malignancies patients treated with cisplatin. Methods: This study is an observational analytic studywith prospective design to determine the influence of high dose cisplatin on cochlear outer hair cellsfunction. The research was carried out at the ENT-HNS Department, Hasan Sadikin General HospitalBandung, from November 2007 until June 2008. Audiometry, tympanometry, and distortion productotoacoustic emission (DPOAE) examinations were conducted before chemotherapy and DPOAE, andtimpanometry was again measured three days after first and second cycles of cisplatin administration. McNemar test was performed to calculate the effects of high-dose cisplatin to the cochlear outer haircells function. To compare pre and post-cisplatin on alteration of cochlear hair cells function, Wilcoxontest was used. Results: In this study 60 ears from 30 subjects that meet the inclusion criteria, consistedof 25 man (83.3%) and 5 women (16.7%). The prevalence of damaged cochlear outer hair cells were63% at first cycle and 70% at second cycle of cisplatin administration. The decline of cochlear outerhair cells function was significant (p<0.001). Conclusion: High-dose cisplatin decreases cochlear outerhair cells function in patients with malignant neoplasm. Abstrak : Latar belakang: Kemoterapi sekarang rutin digunakan secara klinis di seluruh dunia. Sejalan denganhal tersebut toksisitas kemoterapi, khususnya terhadap telinga saat ini menjadi perhatian. Sisplatin(cis-diamminedichloroplatinum) adalah salah satu obat kemoterapi yang paling banyak digunakandan paling manjur untuk terapi keganasan epitelial. Efek ototoksik sisplatin yaitu terjadi gangguandengar sensorineural yang irreversible, progresif, bilateral pada frekuensi tinggi (4-8 kHz), dan disertaidengan tinitus. Tujuan: Untuk menilai penurunan fungsi sel rambut luar koklea pada penderita tumorganas sesudah pemberian sisplatin dosis tinggi dengan menggunakan DPOAE. Metode: Studi analitikobservasional dengan rancangan prospektif di Bagian IK. THT-KL RS. Hasan Sadikin Bandung mulaibulan November 2007 sampai dengan Juni 2008. Pada penelitian ini dilakukan pemeriksaan audiometrinada murni, timpanometri, dan distortion product otoacoustic emission (DPOAE) prakemoterapi, kemudianDPOAE dan timpanometri diulang tiga hari sesudah siklus pertama dan kedua kemoterapi sisplatin. Datayang diperoleh diuji dengan uji McNemar dan uji Wilcoxon. Hasil: Dari penelitian didapat 60 telingadari 30 subjek penelitian yang memenuhi kriteria inklusi yang terdiri dari 25 laki-laki (83,3%) dan 5perempuan (16,7%). Insidens penurunan fungsi sel rambut luar koklea sebesar 63% (38 kasus) sesudahsiklus pertama dan 70% (42 kasus) sesudah siklus kedua. Hubungan penurunan fungsi sel rambut luarkoklea memberikan nilai yang sangat bermakna sejak pemberian siklus pertama (p<0,001). Kesimpulan:Pemberian sisplatin dosis tinggi pada penderita tumor ganas menyebabkan penurunan fungsi sel rambutluar koklea.Kata kunci: kemoterapi, sisplatin dosis tinggi, sel rambut luar koklea.

scholarly journals Optimization of spectral-domain optical coherence tomography with a supercontinuum source for in vivo motion detection of low reflective outer hair cells in guinea pig cochleae

2021 ◽  
Author(s):  
Fumiaki Nin ◽  
Samuel Choi ◽  
Takeru Ota ◽  
Zhang Qi ◽  
Hiroshi Hibino
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Guinea Pig ◽  
Hair Cells ◽  
Sensory Epithelium ◽  
Outer Hair Cells ◽  
Acquisition Time ◽  
Total Acquisition Time ◽  
Sd Oct

AbstractSound evokes sub-nanoscale vibration within the sensory epithelium. The epithelium contains not only immotile cells but also contractile outer hair cells (OHCs) that actively shrink and elongate synchronously with the sound. However, the in vivo motion of OHCs has remained undetermined. The aim of this work is to perform high-resolution and -accuracy vibrometry in live guinea pigs with an SC-introduced spectral-domain optical coherence tomography system (SD-OCT). In this study, to reveal the effective contribution of SC source in the recording of the low reflective materials with the short total acquisition time, we compare the performances of the SC-introduced SD-OCT (SCSD-OCT) to that of the conventional SD-OCT. As inanimate comparison objects, we record a mirror, a piezo actuator, and glass windows. For the measurements in biological materials, we use in/ex vivo guinea pig cochleae. Our study achieved the optimization of a SD-OCT system for high-resolution in vivo vibrometry in the cochlear sensory epithelium, termed the organ of Corti, in mammalian cochlea. By introducing a supercontinuum (SC) light source and reducing the total acquisition time, we improve the axial resolution and overcome the difficulty in recording the low reflective material in the presence of biological noise. The high power of the SC source enables the system to achieve a spatial resolution of 1.72 ± 0.00 μm on a mirror and reducing the total acquisition time contributes to the high spatial accuracy of sub-nanoscale vibrometry. Our findings reveal the vibrations at the apical/basal region of OHCs and the extracellular matrix, basilar membrane.

scholarly journals Neuroplastin expression is essential for hearing and hair cell PMCA expression

2021 ◽  
Author(s):  
Xiao Lin ◽  
Michael G. K. Brunk ◽  
Pingan Yuanxiang ◽  
Andrew W. Curran ◽  
Enqi Zhang ◽  
...  
Keyword(s):  
Hair Cell ◽  
White Noise ◽  
Hair Cells ◽  
Normal Development ◽  
Single Photon ◽  
Photon Emission ◽  
Auditory Brainstem ◽  
Outer Hair Cells ◽  
Emission Computed Tomography ◽  
Cell Degeneration

AbstractHearing deficits impact on the communication with the external world and severely compromise perception of the surrounding. Deafness can be caused by particular mutations in the neuroplastin (Nptn) gene, which encodes a transmembrane recognition molecule of the immunoglobulin (Ig) superfamily and plasma membrane Calcium ATPase (PMCA) accessory subunit. This study investigates whether the complete absence of neuroplastin or the loss of neuroplastin in the adult after normal development lead to hearing impairment in mice analyzed by behavioral, electrophysiological, and in vivo imaging measurements. Auditory brainstem recordings from adult neuroplastin-deficient mice (Nptn−/−) show that these mice are deaf. With age, hair cells and spiral ganglion cells degenerate in Nptn−/− mice. Adult Nptn−/− mice fail to behaviorally respond to white noise and show reduced baseline blood flow in the auditory cortex (AC) as revealed by single-photon emission computed tomography (SPECT). In adult Nptn−/− mice, tone-evoked cortical activity was not detectable within the primary auditory field (A1) of the AC, although we observed non-persistent tone-like evoked activities in electrophysiological recordings of some young Nptn−/− mice. Conditional ablation of neuroplastin in Nptnlox/loxEmx1Cre mice reveals that behavioral responses to simple tones or white noise do not require neuroplastin expression by central glutamatergic neurons. Loss of neuroplastin from hair cells in adult NptnΔlox/loxPrCreERT mice after normal development is correlated with increased hearing thresholds and only high prepulse intensities result in effective prepulse inhibition (PPI) of the startle response. Furthermore, we show that neuroplastin is required for the expression of PMCA 2 in outer hair cells. This suggests that altered Ca2+ homeostasis underlies the observed hearing impairments and leads to hair cell degeneration. Our results underline the importance of neuroplastin for the development and the maintenance of the auditory system.

The tuned displacement response of the hearing organ is generated by the outer hair cells

Neuroscience ◽  
1992 ◽  
Vol 49 (3) ◽  
pp. 607-616 ◽  
Author(s):  
L. Brundin ◽  
Å. Flock ◽  
S.M. Khanna ◽  
M. Ulfendahl
Keyword(s):  
Hair Cells ◽  
Outer Hair Cells ◽  
Displacement Response ◽  
Hearing Organ

scholarly journals Kinetic Membrane Model of Outer Hair Cells

2021 ◽  
Vol 120 (1) ◽  
pp. 122-132
Author(s):  
Kuni H. Iwasa
Keyword(s):  
Hair Cells ◽  
Outer Hair Cells ◽  
Membrane Model

scholarly journals Assessing evidence for adaptive evolution in two hearing-related genes important for high-frequency hearing in echolocating mammals

2021 ◽  
Author(s):  
Hui Wang ◽  
Hanbo Zhao ◽  
Yujia Chu ◽  
Jiang Feng ◽  
Keping Sun
Keyword(s):  
Adaptive Evolution ◽  
Hair Cells ◽  
High Frequency ◽  
Phylogenetic Trees ◽  
Outer Hair Cells ◽  
Functional Domain ◽  
Coding Region ◽  
Selective Pressures ◽  
Wide Range ◽  
Different Parts

Abstract High-frequency hearing is particularly important for echolocating bats and toothed whales. Previously, studies of the hearing-related genes Prestin, KCNQ4, and TMC1 documented that adaptive evolution of high-frequency hearing has taken place in echolocating bats and toothed whales. In this study, we present two additional candidate hearing-related genes, Shh and SK2, that may also have contributed to the evolution of echolocation in mammals. Shh is a member of the vertebrate Hedgehog gene family and is required in the specification of the mammalian cochlea. SK2 is expressed in both inner and outer hair cells, and it plays an important role in the auditory system. The coding region sequences of Shh and SK2 were obtained from a wide range of mammals with and without echolocating ability. The topologies of phylogenetic trees constructed using Shh and SK2 were different; however, multiple molecular evolutionary analyses showed that those two genes experienced different selective pressures in echolocating bats and toothed whales compared to non-echolocating mammals. In addition, several nominally significant positively selected sites were detected in the non-functional domain of the SK2 gene, indicating that different selective pressures were acting on different parts of the SK2 gene. This study has expanded our knowledge of the adaptive evolution of high-frequency hearing in echolocating mammals.

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