Age-related auditory deficits in temporal processing in F-344 rats

Parthasarathy, Aravindakshan; Bartlett, Edward E.

doi:10.1016/j.neuroscience.2011.06.042

Cited by 70 publications

(81 citation statements)

References 54 publications

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“…However, these compensatory mechanisms come at the cost of reduced synchrony of neural representations (Rabang et al 2012). This could result in the some of the decreased EFR amplitudes with age observed in this study and elsewhere (Clinard et al 2010;Parthasarathy and Bartlett 2011;Anderson et al 2012). However, modeling the loss of AN fibers and synapses recreated the majority of the trends observed due to age in this study, suggesting peripheral contributions for the decrease in EFR amplitudes at high SNRs and large AM depths.…”

Section: Effects Of Aging In Processing Simultaneous Sam Tonessupporting

confidence: 50%

“…5). Other studies have also reported agerelated changes at lower SNRs, lower modulation depths, differing envelope shapes and frequency modulation (He et al 2007;Parthasarathy et al 2010;Parthasarathy and Bartlett 2011;Trujillo and Razak 2013). Whether these differences are due to changes in central processing, or some other peripheral effect that is yet to be accounted for, remains to be explored.…”

Section: Effects Of Aging In Processing Simultaneous Sam Tonesmentioning

confidence: 98%

“…Neural deficits due to loss of spiral ganglion and ribbon synapses (Sergeyenko et al 2013) or imbalances in the composition of neurotransmitters (Caspary et al 2008) in the central auditory pathway could account for the deficits seen in temporal processing and sound segregation at suprathreshold sound levels, which persist in subjects with clinically Bnormalĥ earing thresholds (Hind et al 2011). These neural deficits can be detected objectively in both human populations and animal models using auditory evoked potentials such as auditory brainstem responses (ABRs) a n d e n v e l o p e f o l l o w i n g r e s p o n s e s ( E F R s ) (Parthasarathy and Bartlett 2011;Ruggles et al 2012;Sergeyenko et al 2013;Shaheen et al 2015). EFRs represent summed, sustained, synchronized activities of populations of neurons from the auditory pathway which provide additional complementary information to metrics obtained from more established responses like ABRs (Parthasarathy et al 2014), with the major generators being the auditory brainstem and midbrain (Kuwada et al 2002;Chandrasekaran and Kraus 2010;Parthasarathy and Bartlett 2012).…”

Section: Introductionmentioning

confidence: 99%

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Age-Related Changes in Processing Simultaneous Amplitude Modulated Sounds Assessed Using Envelope Following Responses

Parthasarathy

Lai

Bartlett

2016

JARO

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Listening conditions in the real world involve segregating the stimuli of interest from competing auditory stimuli that differ in their sound level and spectral content. It is in these conditions of complex spectrotemporal processing that listeners with age-related hearing loss experience the most difficulties. Envelope following responses (EFRs) provide objective neurophysiological measures of auditory processing. EFRs were obtained to two simultaneous sinusoidally amplitude modulated (sAM) tones from young and aged Fischer-344 rats. One was held at a fixed suprathreshold sound level (sAM1 FL ) while the second varied in sound level (sAM2 VL ) and carrier frequency. EFR amplitudes to sAM1 FL in the young decreased with signal-to-noise ratio (SNR), and this reduction was more pronounced when the sAM2 VL carrier frequency was spectrally separated from sAM1 FL . Aged animals showed similar trends, while having decreased overall response amplitudes compared to the young. These results were replicated using an established computational model of the auditory nerve. The trends observed in the EFRs were shown to be due to the contributions of the lowfrequency tails of high-frequency neurons, rather than neurons tuned to the sAM1 FL carrier frequency. Modeling changes in threshold and neural loss reproduced some of the changes seen with age, but accuracy improved when combined with an additional decrease representing synaptic loss of auditory nerve neurons. Sound segregation in this case derives primarily from peripheral processing, regardless of age. Contributions by more central neural mechanisms are likely to occur only at low SNRs.

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Section: Effects Of Aging In Processing Simultaneous Sam Tonessupporting

confidence: 50%

Section: Effects Of Aging In Processing Simultaneous Sam Tonesmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Age-Related Changes in Processing Simultaneous Amplitude Modulated Sounds Assessed Using Envelope Following Responses

Parthasarathy

Lai

Bartlett

2016

JARO

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“…Human studies using FFRs have found changes in neural timing and precision with age (Tremblay et al 2002(Tremblay et al , 2003Clinard et al 2010;Anderson et al 2012;Clinard and Tremblay 2013). Changes with age have also been observed at the level of single neurons in terms of decreased temporal coding and changes in rate coding in the dorsal cochlear nuclei (Schatteman et al 2008), inferior colliculus (IC) (Walton et al 1998;Palombi et al 2001;Walton et al 2002;Walton 2010;Rabang et al 2012), and auditory cortex (Mendelson and Ricketts 2001) and at a population level using EFRs in rodent aging models (Parthasarathy et al 2010;Parthasarathy and Bartlett 2011;Parthasarathy and Bartlett 2012).…”

Section: Introductionmentioning

confidence: 99%

Age-Related Changes in the Relationship Between Auditory Brainstem Responses and Envelope-Following Responses

Parthasarathy

Datta

Torres

et al. 2014

JARO

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Hearing thresholds and wave amplitudes measured using auditory brainstem responses (ABRs) to brief sounds are the predominantly used clinical measures to objectively assess auditory function. However, frequency-following responses (FFRs) to tonal carriers and to the modulation envelope (envelope-following responses or EFRs) to longer and spectro-temporally modulated stimuli are rapidly gaining prominence as a measure of complex sound processing in the brainstem and midbrain. In spite of numerous studies reporting changes in hearing thresholds, ABR wave amplitudes, and the FFRs and EFRs under neurodegenerative conditions, including aging, the relationships between these metrics are not clearly understood. In this study, the relationships between ABR thresholds, ABR wave amplitudes, and EFRs are explored in a rodent model of aging. ABRs to broadband click stimuli and EFRs to sinusoidally amplitude-modulated noise carriers were measured in young (3-6 months) and aged (22-25 months) Fischer-344 rats. ABR thresholds and amplitudes of the different waves as well as phase-locking amplitudes of EFRs were calculated. Age-related differences were observed in all these measures, primarily as increases in ABR thresholds and decreases in ABR wave amplitudes and EFR phaselocking capacity. There were no observed correlations between the ABR thresholds and the ABR wave amplitudes. Significant correlations between the EFR amplitudes and ABR wave amplitudes were observed across a range of modulation frequencies in the young. However, no such significant correlations were found in the aged. The aged click ABR amplitudes were found to be lower than would be predicted using a linear regression model of the young, suggesting altered gain mechanisms in the relationship between ABRs and FFRs with age. These results suggest that ABR thresholds, ABR wave amplitudes, and EFRs measure complementary aspects of overlapping neurophysiological processes and the relationships between these measurements changes asymmetrically with age. Hence, measuring all three metrics provides a more complete assessment of auditory function, especially under pathological conditions like aging.

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“…Since it is not clear why HI listeners should be more biased than the NH listeners toward the "asynchronous" response, the explanation in terms of uncertainty about the decision appears more likely. Although the correlation shown in Figure 5B did not reveal a systematic relationship between the peak of the synchronous-response functions and listeners' age, some of the differences between the data from the NH and HI listeners may reflect a degraded coding of timing information due to aging and not due to the cochlear hearing loss per se (Fitzgibbons et al 2007;Parthasarathy and Bartlett 2011).…”

Section: Perceived Across-frequency Synchrony and The Cochlear Latencmentioning

confidence: 77%

Perception of Across-Frequency Asynchrony by Listeners with Cochlear Hearing Loss

Wojtczak

Beim

Micheyl

et al. 2013

JARO

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Cochlear hearing loss is often associated with broader tuning of the cochlear filters. Cochlear response latencies are dependent on the filter bandwidths, so hearing loss may affect the relationship between latencies across different characteristic frequencies. This prediction was tested by investigating the perception of synchrony between two tones exciting different regions of the cochlea in listeners with hearing loss. Subjective judgments of synchrony were compared with thresholds for asynchrony discrimination in a three-alternative forced-choice task. In contrast to earlier data from normal-hearing (NH) listeners, the synchronous-response functions obtained from the hearing-impaired (HI) listeners differed in patterns of symmetry and often had a very low peak (i.e., maximum proportion of "synchronous" responses). Also in contrast to data from NH listeners, the quantitative and qualitative correspondence between the data from the subjective and the forced-choice tasks was often poor. The results do not provide strong evidence for the influence of changes in cochlear mechanics on the perception of synchrony in HI listeners, and it remains possible that age, independent of hearing loss, plays an important role in temporal synchrony and asynchrony perception.

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Age-related auditory deficits in temporal processing in F-344 rats

Cited by 70 publications

References 54 publications

Age-Related Changes in Processing Simultaneous Amplitude Modulated Sounds Assessed Using Envelope Following Responses

Age-Related Changes in Processing Simultaneous Amplitude Modulated Sounds Assessed Using Envelope Following Responses

Age-Related Changes in the Relationship Between Auditory Brainstem Responses and Envelope-Following Responses

Perception of Across-Frequency Asynchrony by Listeners with Cochlear Hearing Loss

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