Tinnitus and Neural Activity

1983 ◽  
Vol 26 (4) ◽  
pp. 629-632 ◽  
Author(s):  
Richard J. Salvi ◽  
William A. Ahroon
Keyword(s):  
Hearing Loss ◽  
Neural Activity ◽  
Auditory Nerve ◽  
High Frequency ◽  
Discharge Rate ◽  
Nerve Fibers ◽  
Spontaneous Discharge ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Discharge Rates

The spontaneous discharge rates of auditory nerve fibers were measured in a group of normal chinchillas and in a group of chinchillas with high-frequency, noise-induced hearing loss. In contrast to normal units, the high-frequency units in the noise-exposed animals tended to have elevated spontaneous discharge rates, high thresholds, and a lack of two-tone inhibition. The change in spontaneous discharge rate across the distribution of nerve fibers is related to models of tinnitus and to human psychophysical data.

scholarly journals Spatiotemporal Developmental Upregulation of Prestin Correlates With the Severity and Location of Cyclodextrin-Induced Outer Hair Cell Loss and Hearing Loss

2021 ◽  
Vol 9 ◽  
Author(s):  
Dalian Ding ◽  
Haiyan Jiang ◽  
Senthilvelan Manohar ◽  
Xiaopeng Liu ◽  
Li Li ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
Auditory Nerve ◽  
High Frequency ◽  
Spiral Ganglion ◽  
Low Frequency ◽  
Nerve Fibers ◽  
Spiral Ganglion Neurons ◽  
Auditory Nerve Fibers ◽  
Ganglion Neurons

2-Hyroxypropyl-beta-cyclodextrin (HPβCD) is being used to treat Niemann-Pick C1, a fatal neurodegenerative disease caused by abnormal cholesterol metabolism. HPβCD slows disease progression, but unfortunately causes severe, rapid onset hearing loss by destroying the outer hair cells (OHC). HPβCD-induced damage is believed to be related to the expression of prestin in OHCs. Because prestin is postnatally upregulated from the cochlear base toward the apex, we hypothesized that HPβCD ototoxicity would spread from the high-frequency base toward the low-frequency apex of the cochlea. Consistent with this hypothesis, cochlear hearing impairments and OHC loss rapidly spread from the high-frequency base toward the low-frequency apex of the cochlea when HPβCD administration shifted from postnatal day 3 (P3) to P28. HPβCD-induced histopathologies were initially confined to the OHCs, but between 4- and 6-weeks post-treatment, there was an unexpected, rapid and massive expansion of the lesion to include most inner hair cells (IHC), pillar cells (PC), peripheral auditory nerve fibers, and spiral ganglion neurons at location where OHCs were missing. The magnitude and spatial extent of HPβCD-induced OHC death was tightly correlated with the postnatal day when HPβCD was administered which coincided with the spatiotemporal upregulation of prestin in OHCs. A second, massive wave of degeneration involving IHCs, PC, auditory nerve fibers and spiral ganglion neurons abruptly emerged 4–6 weeks post-HPβCD treatment. This secondary wave of degeneration combined with the initial OHC loss results in a profound, irreversible hearing loss.

Development of resistance to hearing loss from high frequency noise

1991 ◽  
Vol 56 (1-2) ◽  
pp. 65-68 ◽  
Author(s):  
Malini Subramaniam ◽  
Pierre Campo ◽  
Donald Henderson
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Development Of Resistance

Neural mechanisms of tone-on-tone masking: patterns of discharge rate and discharge synchrony related to rates of spontaneous discharge in the chinchilla auditory nerve

1986 ◽  
Vol 56 (6) ◽  
pp. 1763-1780 ◽  
Author(s):  
D. G. Sinex ◽  
D. C. Havey
Keyword(s):  
Auditory Nerve ◽  
Average Rate ◽  
Discharge Rate ◽  
Quantitative Agreement ◽  
Nerve Fibers ◽  
Spontaneous Discharge ◽  
Probe Tone ◽  
Distortion Products ◽  
Auditory Nerve Fibers ◽  
Psychophysical Studies

Responses of chinchilla auditory nerve fibers to brief probe tones in the presence of a fixed tonal masker were obtained. The stimulus conditions were analogous to those that have been used in many psychophysical experiments. The relation between previously described response properties of auditory nerve fibers and features of psychophysical tone-on-tone masking was examined. In psychophysical studies, a fixed narrowband masker produces a characteristic pattern of masked thresholds, which becomes broad and asymmetrical at high masker levels. In the present experiment 1, a 5,000-Hz masker was presented at 30, 50, and 70 dB SPL. Masked thresholds based on the average rate of response to probe tones were estimated for single auditory nerve fibers. The lowest of these masked thresholds formed a pattern similar to the psychophysical masking pattern, becoming broader and more asymmetrical as the masker was increased to 70 dB SPL. The masked thresholds of fibers with low and medium rates of spontaneous discharge (SR) were as low as or lower than the masked thresholds of fibers with high SRs. In certain frequency regions, masked thresholds based on responses to cochlear distortion products were lower than the masked thresholds of any fiber responding to the probe tone; this result is also similar to previous psychophysical observations. In experiment 2, responses of chinchilla auditory nerve fibers to probe tones in the presence of a masker at 1,000 Hz and 50 dB SPL were studied. Probe tone thresholds in the presence of this masker have been measured psychophysically in chinchillas. Thus the relation between behavioral and neural masked thresholds in the same species could be examined. Masked thresholds were estimated from average discharge rate responses and also from discharge synchrony. Good quantitative agreement was observed between the probe tone levels at which changes in average discharge rate were observed and the chinchilla's behavioral masked thresholds. For fibers matched for characteristic frequency, the masked thresholds based on average discharge rate of high-SR fibers tended to be elevated compared with the thresholds of medium-SR fibers. Changes in discharge rate synchronized to the probe tone occurred at levels lower than the chinchilla's behavioral masked thresholds. If discharge synchrony can be used for detection, the code would appear to be based on the relative synchrony to the probe tone and to the masking tone. Low synchrony masked thresholds were obtained from fibers with all SRs.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Probing adaptation and spontaneous firing in human auditory-nerve fibers with far-field peri-stimulus time responses

2021 ◽  
Author(s):  
Antoine Huet ◽  
Charlène Batrel ◽  
Xavier Dubernard ◽  
Jean-Charles Kleiber ◽  
Gilles Desmadryl ◽  
...  
Keyword(s):  
Auditory Nerve ◽  
Round Window ◽  
Nerve Fibers ◽  
Electrical Signal ◽  
Cochlear Nerve ◽  
Spontaneous Discharge ◽  
Rapid Adaptation ◽  
Discharge Rates ◽  
Auditory Nerve Fibers ◽  
Stimulus Time

AbstractInformation in sound stimuli is conveyed from sensory hair cells to the cochlear nuclei by the firing of auditory nerve fibers (ANFs). For obvious ethical reasons, single unit recordings from the cochlear nerve have never been performed in human, thus functional hallmarks of ANFs are unknown. By filtering and rectifying the electrical signal recorded at the round window of gerbil cochleae, we reconstructed a peri-stimulus time response (PSTR), with a waveform similar to the peri-stimulus time histograms (PSTHs) recorded from single ANFs. Pair-by-pair analysis of simultaneous PSTR and PSTH recordings in gerbil provided a model to predict the rapid adaptation and spontaneous discharge rates (SR) in a population of ANFs according to their location in the cochlea. We then probed the model in the mouse, in which the SR-based distribution of ANFs differs from the gerbil. We show that the PSTR-based predictions of the rapid adaptation time constant and mean SR across frequency again matched those obtained by recordings from single ANFs. Using PSTR recorded from the human cochlear nerve in 8 normal-hearing patients who underwent cerebellopontine angle surgeries for a functional cranial-nerve disorders (trigeminal neuralgia or hemifacial spasm), we predicted a rapid adaptation of about 3 milliseconds and a mean SR of 23 spikes/s in the 4 kHz frequency range in human ANFs. Together, our results support the use of PSTR as a promising diagnostic tool to map the auditory nerve in humans, thus opening new avenues to better understanding neuropathies, tinnitus, and hyperacusis.

Gap Detection as a Function of Stimulus Loudness for Listeners With and Without Hearing Loss

1997 ◽  
Vol 40 (6) ◽  
pp. 1387-1394 ◽  
Author(s):  
Peggy B. Nelson ◽  
Susan Dwyer Thomas
Keyword(s):  
Hearing Loss ◽  
Temporal Resolution ◽  
High Frequency ◽  
Normal Hearing ◽  
Frequency Noise ◽  
Gap Detection ◽  
Detection Ability ◽  
High Frequency Noise ◽  
Wide Range ◽  
Comfortable Loudness

Temporal resolution, or the ability to process rapidly changing stimuli, has been purported to be reduced in some listeners with hearing loss while being described as normal in others. Ensuring stimulus audibility by increasing stimulus levels results in near-normal temporal resolution abilities for many listeners with hearing loss, but may also result in uncomfortably loud stimulus levels. The current study was conducted to describe temporal resolution abilities of listeners with and without hearing loss as a function of stimulus loudness. The gap detection abilities of 8 listeners with normal hearing were compared with those of 8 listeners with mild to moderate hearing losses over a wide range of intensities using a 650-Hz wide high-frequency noise marker. At low intensities, listeners with hearing loss show poor gap detection ability. As intensity increases, most listeners’ performance improves and stabilizes near normal at high loudness and sensation levels. At comfortable loudness, gap detection abilities of listeners with hearing loss are less than at loud levels and are considerably poorer than normal.

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