Altered cortical spectrotemporal processing with age-related hearing loss

Trujillo, Michael; Razak, Khaleel A.

doi:10.1152/jn.00423.2013

Cited by 21 publications

(11 citation statements)

References 95 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Animal research has shown a direct association between decline in auditory neural selectivity and age-related hearing loss (33,49). If GABA levels influence neural distinctiveness, as our results suggest, then pharmacological treatments that target GABA could be a promising avenue for clinical research aimed at mitigating age-related hearing impairments.…”

Section: Auditory Gaba Decline Predicts Dedifferentiationmentioning

confidence: 63%

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Lalwani

Gagnon

Cassady

et al. 2018

Preprint

View full text Add to dashboard Cite

Neural activation patterns in the ventral visual cortex in response to different categories of visual stimuli (e.g., faces vs. houses) are less selective, or distinctive, in older adults than in younger adults, a phenomenon known as age-related neural dedifferentiation. Previous work in animals suggests that age-related reductions of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA), may play a role in this age-related decline in neural distinctiveness.In this study, we investigated whether neural dedifferentiation extends to auditory cortex and whether individual differences in GABA are associated with individual differences in neural distinctiveness in humans. 20 healthy young adults (ages 18-29) and 23 healthy older adults (over 65) completed a functional magnetic resonance imaging (fMRI) scan, during which neural activity was estimated while they listened to foreign speech and music. GABA levels in the auditory, ventrovisual and sensorimotor cortex were estimated in the same individuals in a separate magnetic resonance spectroscopy (MRS) scan. Relative to the younger adults, the older adults exhibited both (1) less distinct activation patterns for music vs. speech stimuli and (2) lower GABA levels in the auditory cortex. Also, individual differences in auditory GABA levels (but not ventrovisual or sensorimotor GABA levels) predicted individual differences in neural distinctiveness in the auditory cortex in the older adults. These results demonstrate that agerelated neural dedifferentiation extends to the auditory cortex and suggest that declining GABA levels may play a role in neural dedifferentiation in older adults. Significance StatementPrior work has revealed age-related neural dedifferentiation in the visual cortex. GABA levels also decline with age in several parts of the human cortex. Here, we report that these two agerelated changes are linked; neural dedifferentiation is associated with lower GABA levels in older adults. We also show that age-related neural dedifferentiation extends to auditory cortex, suggesting that it may be a general feature of the aging brain. These findings provide novel insights into the neurochemical basis of age-related neural dedifferentiation in humans and also offer a potential new avenue for investigating age-related declines in central auditory processing.

show abstract

Section: Auditory Gaba Decline Predicts Dedifferentiationmentioning

confidence: 63%

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Lalwani

Gagnon

Cassady

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…The PV+ cells may shape inhibitory components of receptive fields and responses to rapid spectrotemporal cues (Atencio and Schreiner, 2008; Wu et al, 2008). Reduced inhibition may underlie spectrotemporal processing and speech recognition deficits with age (Walton et al, 1998; Mendelson and Ricketts, 2001; Razak and Fuzessery, 2009; Parthasarathy and Bartlett, 2011; Suta et al, 2011; Trujillo and Razak, 2013). …”

Section: Discussionmentioning

confidence: 99%

“…Processing of rapidly changing spectrotemporal cues, such as those present in speech, depends on interactions between excitatory and inhibitory components of the auditory neuron receptive field (Zhang et al, 2003; Razak and Fuzessery, 2006, 2008, 2009; Sadagopan and Wang, 2010; Trujillo et al, 2013). Reduced inhibition may, therefore, affect temporal and spectrotemporal processing, and cause speech processing deficits with age (Walton et al, 1998; Mendelson and Ricketts, 2001; Parthasarathy and Bartlett, 2011; Suta et al, 2011; Trujillo and Razak, 2013). The cellular correlates of reduced inhibition in the auditory system remain incompletely characterized.…”

Section: Introductionmentioning

confidence: 99%

Age-Related Deterioration of Perineuronal Nets in the Primary Auditory Cortex of Mice

Brewton

Kokash

Jimenez

et al. 2016

Front. Aging Neurosci.

Self Cite

View full text Add to dashboard Cite

Age-related changes in inhibitory neurotransmission in sensory cortex may underlie deficits in sensory function. Perineuronal nets (PNNs) are extracellular matrix components that ensheath some inhibitory neurons, particularly parvalbumin positive (PV+) interneurons. PNNs may protect PV+ cells from oxidative stress and help establish their rapid spiking properties. Although PNN expression has been well characterized during development, possible changes in aging sensory cortex have not been investigated. Here we tested the hypothesis that PNN+, PV+ and PV/PNN co-localized cell densities decline with age in the primary auditory cortex (A1). This hypothesis was tested using immunohistochemistry in two strains of mice (C57BL/6 and CBA/CaJ) with different susceptibility to age-related hearing loss and at three different age ranges (1–3, 6–8 and 14–24 months old). We report that PNN+ and PV/PNN co-localized cell densities decline significantly with age in A1 in both mouse strains. In the PNN+ cells that remain in the old group, the intensity of PNN staining is reduced in the C57 strain, but not the CBA strain. PV+ cell density also declines only in the C57, but not the CBA, mouse suggesting a potential exacerbation of age-effects by hearing loss in the PV/PNN system. Taken together, these data suggest that PNN deterioration may be a key component of altered inhibition in the aging sensory cortex, that may lead to altered synaptic function, susceptibility to oxidative stress and processing deficits.

show abstract

“…Although a direct link between presbycusis and age-related degradation of SMI-32 immunoreactivity is still yet to be revealed, there are physiological alterations indicating deteriorated function of fast conducting neurons that may potentially involve SMI-32-ir neurons. In rodents, these alteration include deteriorated processing of fast FM sweeps ( Mendelson and Ricketts, 2001 ), slowing down of responses to the FM sweeps or increased variability to the same auditory stimuli ( Trujillo and Razak, 2013 ).…”

Section: Discussionmentioning

confidence: 99%

The influence of aging on the number of neurons and levels of non-phosporylated neurofilament proteins in the central auditory system of rats

Burianová

Ouda

Syka

2015

Front. Aging Neurosci.

View full text Add to dashboard Cite

In the present study, an unbiased stereological method was used to determine the number of all neurons in Nissl stained sections of the inferior colliculus (IC), medial geniculate body (MGB), and auditory cortex (AC) in rats (strains Long Evans and Fischer 344) and their changes with aging. In addition, using the optical fractionator and western blot technique, we also evaluated the number of SMI-32-immunoreactive (-ir) neurons and levels of non-phosphorylated neurofilament proteins in the IC, MGB, AC, and visual cortex of young and old rats of the two strains. The SMI-32 positive neuronal population comprises about 10% of all neurons in the rat IC, MGB, and AC and represents a prevalent population of large neurons with highly myelinated and projecting processes. In both Long Evans and Fischer 344 rats, the total number of neurons in the IC was roughly similar to that in the AC. With aging, we found a rather mild and statistically non-significant decline in the total number of neurons in all three analyzed auditory regions in both rat strains. In contrast to this, the absolute number of SMI-32-ir neurons in both Long Evans and Fischer 344 rats significantly decreased with aging in all the examined structures. The western blot technique also revealed a significant age-related decline in the levels of non-phosphorylated neurofilaments in the auditory brain structures, 30–35%. Our results demonstrate that presbycusis in rats is not likely to be primarily associated with changes in the total number of neurons. On the other hand, the pronounced age-related decline in the number of neurons containing non-phosphorylated neurofilaments as well as their protein levels in the central auditory system may contribute to age-related deterioration of hearing function.

show abstract

Altered cortical spectrotemporal processing with age-related hearing loss

Cited by 21 publications

References 95 publications

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Neural distinctiveness declines with age in auditory cortex and is associated with auditory GABA levels

Age-Related Deterioration of Perineuronal Nets in the Primary Auditory Cortex of Mice

The influence of aging on the number of neurons and levels of non-phosporylated neurofilament proteins in the central auditory system of rats

Contact Info

Product

Resources

About