Age-related decrease of GABAA receptor subunits and glutamic acid decarboxylase in the rat inferior colliculus

Gutiérrez, Antonia; Khan, Z U; Morris, SJ; Blas, AL de

doi:10.1523/jneurosci.14-12-07469.1994

Cited by 94 publications

(61 citation statements)

References 48 publications

(58 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other investigations have been performed on age-related changes in the whole GABAergic system, such as the loss of GABA neurons [34], decreased levels of the enzyme needed to synthesize GABA [2], and some alterations in GABA A subunits and in the combination of the subunits [2,4]. Therefore, the present data support the current hypothesis by suggesting a reduction in GABA-mediated inhibition in the senescent brain.…”

Section: Discussionsupporting

confidence: 88%

See 1 more Smart Citation

Differential effects of aging on EEG after baclofen administration

Cui

2011

Sci. China Life Sci.

View full text Add to dashboard Cite

Baclofen is a selective gamma-aminobutyric acid (GABA) type B agonist that may have important medicinal uses, such as in analgesics and drug addiction treatment. In addition, evidence is accumulating that suggests GABAergic-mediated neurotransmission is altered during aging. This study investigated whether baclofen administration (5 mg kg −1 ) induces differential effects on cortical electrical activity with age. Electroencephalograms (EEGs) were recorded from young (3-4 months) and aged (15-17 months) rats, and both the absolute and relative powers in five frequency bands (delta: 2-4 Hz; theta: 4-8 Hz; alpha: 8-12 Hz; beta: 12-20 Hz; gamma: 20-100 Hz) were analyzed. Before administration of baclofen, we found that the EEG relative power in the beta band was higher in the aged than that in the young rats. After administration of baclofen, there was a slower increase in the relative power in the delta band in the aged than that in the young rats. Moreover, there was no significant difference between the two age groups in absolute power in any frequency band. These findings indicate that baclofen treatment appears to differentially modify cortical EEG activity as a function of age. Our data further elucidate the relationship between GABA B receptor-mediated neurotransmission and aging.aging, baclofen, EEG, spectra power, rat Citation:

show abstract

Section: Discussionsupporting

confidence: 88%

“…For example, GABA production may decrease in old monkeys [1]. Levels of glutamic acid decarboxylase, an enzyme needed to synthesize GABA, have also been observed to decrease with age [2]. Moreover, both GABA A and GABA B receptors exhibit some alterations in their subunits or at their binding sites during aging [2][3][4][5].…”

mentioning

confidence: 99%

Differential effects of aging on EEG after baclofen administration

Cui

2011

Sci. China Life Sci.

View full text Add to dashboard Cite

show abstract

“…Age-related loss of markers for inhibitory amino acids has also been described for the auditory midbrain. The inferior colliculus (IC) shows significant age-related changes related to GABA neurotransmission in rats (Banay-Schwartz et al, 1989;Caspary et al, 1990Caspary et al, , 1995Gutierrez et al, 1994;Milbrandt et al, 1994;Raza et al, 1994) and the loss of GABAimmunoreactive synaptic endings. Postmortem human studies of the cortex and IC are less clear.…”

Section: Discussionmentioning

confidence: 99%

Age-Related Changes in the Inhibitory Response Properties of Dorsal Cochlear Nucleus Output Neurons: Role of Inhibitory Inputs

Caspary

Schatteman²,

Hughes³

2005

J. Neurosci.

158

114

View full text Add to dashboard Cite

Age-related hearing loss frequently results in a loss in the ability to discriminate speech signals, especially in noise. This is attributable, in part, to a loss in temporal resolving power and ability to adjust dynamic range. Circuits in the adult dorsal cochlear nucleus (DCN) have been shown to preserve signal in background noise. Fusiform cells, major DCN output neurons, receive focused glycinergic inputs from tonotopically aligned vertical cells that also project to the ventral cochlear nucleus. Glycine-mediated inhibition onto fusiform cells results in decreased tone-evoked activity as intensity is increased at frequencies adjacent to characteristic frequency (CF). DCN output is thus shaped by glycinergic inhibition, which can be readily assessed in recordings from fusiform cells. Previous DCN studies suggest an age-related loss of markers for glycinergic neurotransmission. The present study postulated that response properties of aged fusiform cells would show a loss of inhibition, resembling conditions observed with glycine receptor blockade. The functional impact of aging was examined by comparing response properties from units meeting fusiform-cell criteria in young and aged rats. Fusiform cells in aged animals displayed significantly higher maximum discharge rates to CF tones than those recorded from young-adult animals. Fusiform cells of aged rats displayed significantly fewer nonmonotonic CF rate-level functions and an age-related change in temporal response properties. These findings are consistent with an age-related loss of glycinergic input, likely from vertical cells, and with findings from other sensory aging studies suggesting a selective age-related decrement in inhibitory amino acid neurotransmitter function.

show abstract

Section: Low Cf Unitsmentioning

confidence: 99%

“…Although the HI mice in the present study are not old, they are uniformly older than the NH mice. Thus, age-related alterations in GABA and GABA receptors within the IC, which have been shown to develop with age (Gutierrez et al, 1994,Caspary et al, 1995,Caspary et al, 1999, may contribute to a change in the inhibitory/excitatory balance in the IC itself.A final indicator of altered inhibition can be changes in the units' temporal response patterns (Vater et al, 1992;Le Beau et al, 1996), and the low/broad units in this study changed towards more sustained responding in the HI IC. There is little consistency in the literature about the effects of hearing loss on response patterns.…”

mentioning

confidence: 99%

Reorganization of receptive fields following hearing loss in inferior colliculus neurons

Barsz¹,

Wilson²,

Walton³

2007

Neuroscience

View full text Add to dashboard Cite

We explored frequency and intensity encoding in the inferior colliculus of the C57 mouse model of sensorineural hearing loss. Consistent with plasticity reported in the IC of other models of hearing loss, frequency response areas (FRAs) in hearing impaired (HI) mice were broader with fewer highfrequency units than normal-hearing (NH) mice. The broad FRAs recorded from HI mice had lower cutoffs on the low frequency edge of the FRA. Characteristic frequency (CF) and sharpness of tuning (Q10) calculated from the FRA were used to divide the sample into 4 categories: low-CF sharp-FRA, low-CF broad-FRA, high-CF sharp-FRA, and high-CF broad-FRA units. Rate-intensity functions (RIFs) for CF tones and noise were used to determine the minimum and maximum response counts as well as the sound pressure levels resulting in 10%, 50%, and 90% of the maximum spike count. Tone RIFs of broad FRA units were shifted to the right of tone RIFs of sharp FRA units in both NH and HI mouse IC, regardless of the unit CF. The main effects of hearing loss were seen in the noise RIFs. The low-CF broad-FRA units in HI mice had elevated response to noise, and the high-CF sharp-FRA units in HI mice had lower maximum rates, as compared to the units recorded from NH mice. These results suggest that, as the IC responds to peripheral hearing loss with changes in the representation of frequency, an altered balance between inhibitory and excitatory inputs to the neurons recorded from the HI mice alter aspects of the units' intensity encoding. This altered balance likely occurs, at least in part, outside of the IC. Keywords plasticity; sensorineural hearing loss; C57 mouse; intensity encoding; central auditory nervous system Sensorineural hearing loss occurs in almost 10% of the US population. One of the most debilitating side effects of this condition is difficulty with word comprehension, particularly when the listening environment is noisy (Needleman and Crandell, 1995). Treatment of hearing loss includes amplification, but it cannot be assumed that amplification restores normal perception. For instance, hearing loss alters the frequency tuning curves and rate-intensity functions (RIFs) in central auditory neurons (Willott, 1984, Willott, 1986, and these deficits cannot be compensated by simple amplification alone. In addition, the sensitivity of the auditory system of hearing impaired listeners may be altered by long-term amplification. ForCorresponding Author: Joseph P. Walton, Department of Otolaryngology and Neurobiology and Anatomy, University of Rochester Medical School, 601 Elmwood Ave., Rochester, NY 14642, USA, Joseph_Walton@URMC.rochester.edu, PHONE: 585-275-1248, FAX: 585-244-4103. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that durin...

show abstract

Age-related decrease of GABAA receptor subunits and glutamic acid decarboxylase in the rat inferior colliculus

Cited by 94 publications

References 48 publications

Differential effects of aging on EEG after baclofen administration

Differential effects of aging on EEG after baclofen administration

Age-Related Changes in the Inhibitory Response Properties of Dorsal Cochlear Nucleus Output Neurons: Role of Inhibitory Inputs

Reorganization of receptive fields following hearing loss in inferior colliculus neurons

Contact Info

Product

Resources

About