A5035701879- Hearing, Cochlea, Tinnitus, Genetics
- Hearing Loss and Rehabilitation
- Vestibular and auditory disorders
- Noise Effects and Management
- Acoustic Wave Phenomena Research
- Ear Surgery and Otitis Media
- Biochemical Analysis and Sensing Techniques
- Ion Channels and Receptors
- Neural dynamics and brain function
- Animal Vocal Communication and Behavior
- Nicotinic Acetylcholine Receptors Study
- Marine animal studies overview
- Neuroscience of respiration and sleep
- Photoreceptor and optogenetics research
- Music and Audio Processing
- RNA regulation and disease
- Speech and Audio Processing
- Neurogenesis and neuroplasticity mechanisms
- Connexins and lens biology
- Neuroscience and Neuropharmacology Research
- Alcoholism and Thiamine Deficiency
- Underwater Acoustics Research
- Augmented Reality Applications
- Computer Graphics and Visualization Techniques
- Advanced Chemical Sensor Technologies
Massachusetts Eye and Ear Infirmary
2015-2024
Harvard University
2015-2024
Eaton (United States)
2017-2024
Massachusetts Institute of Technology
1997-2016
Peabody
1984-2015
Harvard–MIT Division of Health Sciences and Technology
1995-2014
Harvard University Press
2003-2012
Eaton (Taiwan)
1984-2009
Fundación Ciencias Exactas y Naturales
2007
University of Buenos Aires
2007
Overexposure to intense sound can cause temporary or permanent hearing loss. Postexposure recovery of threshold sensitivity has been assumed indicate reversal damage delicate mechano-sensory and neural structures the inner ear no persistent delayed consequences for auditory function. Here, we show, using cochlear functional assays confocal imaging in mouse, that acoustic overexposures causing moderate, but completely reversible, elevation leave sensory cells intact, acute loss afferent nerve...
A litter of four cats, born and raised in a soundproofed chamber, was studied an attempt to determine which, if any, features the auditory-nerve response from routinely available cats might be due chronic effects noise exposure. Two routine-normal were especially suspect this regard: (1) ’’notch’’ distribution single-unit thresholds centered at characteristic frequencies (CF’s) near 3 kHz (2) compression rates spontaneous discharge for units with CF above 10 kHz. third feature routine...
Aging listeners experience greater difficulty understanding speech in adverse listening conditions and exhibit degraded temporal resolution, even when audiometric thresholds are normal. When threshold evidence for peripheral involvement is lacking, central cognitive factors often cited as underlying performance declines. However, previous work has uncovered widespread loss of cochlear afferent synapses progressive nerve degeneration noise-exposed ears with recovered no hair cell (Kujawa...
Acoustic overexposure can cause a permanent loss of auditory nerve fibers without destroying cochlear sensory cells, despite complete recovery thresholds (Kujawa and Liberman 2009), as measured by gross neural potentials such the brainstem response (ABR). To address this nominal paradox, we recorded responses from single in guinea pigs exposed to type neuropathic noise (4- 8-kHz octave band at 106 dB SPL for 2 h). Two weeks postexposure, ABR had recovered normal, while suprathreshold...
Age-related and noise-induced hearing losses in humans are multifactorial, with contributions from, potential interactions among, numerous variables that can shape final outcome. A recent retrospective clinical study suggests an age-noise interaction exacerbates age-related loss previously noise-damaged ears (Gates et al., 2000). Here, we address the issue animal model by comparing (NIHL; AHL) groups of CBA/CaJ mice exposed identically (8-16 kHz noise band at 100 dB sound pressure level for...
Recent work suggests that hair cells are not the most vulnerable elements in inner ear; rather, it is synapses between and cochlear nerve terminals degenerate first aging or noise-exposed ear. This primary neural degeneration does affect hearing thresholds, but likely contributes to problems understanding speech difficult listening environments, may be important generation of tinnitus and/or hyperacusis. To look for signs synaptopathy humans, we recruited college students divided them into...
Single auditory nerve fibers in the cat were labeled intracellularly with horseradish peroxidase. The sample of was selected to represent different response types over a wide range characteristic frequencies. All 56 neurons found be radial innervating inner hair cells, suggesting that none single-unit data reported date has been from outer cell innervation. Differences rates spontaneous discharge and thresholds tones among these closely correlated morphological differences caliber location...
The availability of transgenic and mutant lines makes the mouse a valuable model for study inner ear, powerful window into cochlear function can be obtained by recordings from single auditory nerve (AN) fibers. This provides first systematic description spontaneous sound-evoked discharge properties AN fibers in mouse, specifically CBA/CaJ C57BL/6 strains, both commonly used research. Response 196 58 were analyzed, including rates (SR), tuning curves, rate versus level functions, dynamic...
Iontophoresis of horseradish peroxidase was used to label single auditory nerve fibers after determination threshold tuning curves and rates spontaneous discharge. The relation between characteristic frequency (CF) cochlear longitudinal location is reconstructed from 52 labeled neurons in 16 cochleas. length the organ Corti alotted an octave stimulus increases steadily low high frequencies. Thus there not a simple linear- distance-to-log conversion. When comparing cochleas different total...
The purpose of the present study was to describe longitudinal and radial gradients cochlear innervation in cat. To this end, afferent efferent terminals both inner (IHC) outer hair cell (OHC) regions were reconstructed from serial ultrathin sections at six eight locations, respectively, corresponding roughly octave intervals characteristic frequency (CF). Analysis IHCs showed 1) number fibers per IHC rises 10 0.25 kHz region a maximum 30 locus; 2) branching is essentially restricted apical...
Highlights•Hair-cell and auditory-nerve loss were quantified in 20 "normal" humans 0–86 yrs.•Age-related of nerve fibers exceeded the rate hair cell by almost 3:1.•In 10/16 ears over 50 yrs, >50% connections had degenerated.•This neural degeneration degrades hearing ability without affecting audiogram.AbstractThe noise-induced age-related synaptic between cochlear cells is well-established from histopathology several mammalian species; however, its prevalence humans, as inferred...
Cochlear synaptic loss, rather than hair cell death, is the earliest sign of damage in both noise- and age-related hearing impairment (Kujawa Liberman, 2009; Sergeyenko et al., 2013). Here, we compare cochlear aging after two types noise exposure: one producing permanent without loss another neither synaptopathy nor loss. Adult mice were exposed (8–16 kHz, 100 or 91 dB SPL for 2 h) then evaluated from 1 h to ∼20 months exposure. function was assessed via distortion product otoacoustic...