Reorganization of auditory cortex after neonatal high frequency cochlear hearing loss

Harrison, Robert V.; Nagasawa, Akira; Smith, D.W.; Stanton, Susan G.; Mount, Richard J.

doi:10.1016/0378-5955(91)90131-r

Cited by 117 publications

(55 citation statements)

References 20 publications

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“…Perinatal lesion of the cochlea leads to disrupted tonotopic representations in both the inferior colliculus and the A1 (34,35), potentially explaining the increased latency recorded for peak V. The inferior colliculus is also one of the most metabolically active structures in the brain (36), and it therefore represents a vulnerable target to PA. Interestingly, neuronal proliferation in the inferior colliculus is prominent, and middlefrequency inputs are arriving in this nucleus in the immediate postnatal period in the rat (29,37).…”

Section: Discussionmentioning

confidence: 99%

Perinatal anoxia degrades auditory system function in rats

Strata

Deipolyi²,

Bonham³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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Little is known about the neural bases of the reduced auditory and cortical processing speeds that have been recorded in languageimpaired, autistic, schizophrenic, and other disabled human populations. Although there is strong evidence for genetic contributions to etiologies, epigenetic factors such as perinatal anoxia (PA) have been argued to be contributors, or causal, in a significant proportion of cases. In this article, we explored the consequences of PA on this elementary aspect of auditory behavior and on auditory system function in rats that were briefly perinatally anoxic. PA rats had increased acoustic thresholds and reduced processing efficiencies recorded in an auditory behavioral task. These rats had modestly increased interpeak intervals in their auditory brainstem responses, and substantially longer latencies in poststimulus time histogram responses recorded in the primary auditory cortex. The latter were associated with degraded primary auditory cortex receptive fields and a disrupted tonotopy. These processing deficits are consistent with the parallel behavioral and physiological deficits recorded in children and adults with a history of language-learning impairment and autism.auditory behavior ͉ auditory brainstem responses ͉ auditory cortex ͉ autism ͉ language learning impairment

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Section: Discussionmentioning

confidence: 99%

Perinatal anoxia degrades auditory system function in rats

Strata

Deipolyi²,

Bonham³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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“…This functional reorganization is evidenced mainly by two kinds of significant changes in the central auditory system activity: (1) reorganization of frequency maps in the auditory cortex, and (2) alterations in neural responses and binaural interactions at various levels in the auditory pathways. These changes have been demonstrated in both the developing (Harrison et al 1991;Kitzes 1984;Reale et al 1987;Eggermont and Komiya 2000) and the mature (Popelár et al 1994;Rajan et al 1993; Robertson and Irvine 1989) auditory system.…”

Section: Introductionmentioning

confidence: 95%

Differential Ear Effects of Profound Unilateral Deafness on the Adult Human Central Auditory System

Khosla

Ponton

Eggermont

et al. 2003

JARO - Journal of the Association for Research in Otolaryngolog

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This study investigates the effects of profound acquired unilateral deafness on the adult human central auditory system by analyzing long-latency auditory evoked potentials (AEPs) with dipole source modeling methods. AEPs, elicited by clicks presented to the intact ear in 19 adult subjects with profound unilateral deafness and monaurally to each ear in eight adult normal-hearing controls, were recorded with a 31-channel system. The responses in the 70-210 ms time window, encompassing the N 1b /P 2 and Ta/Tb components of the AEPs, were modeled by a vertically and a laterally oriented dipole source in each hemisphere. Peak latencies and amplitudes of the major components of the dipole waveforms were measured in the hemispheres ipsilateral and contralateral to the stimulated ear. The normal-hearing subjects showed significant ipsilateral-contralateral latency and amplitude differences, with contralateral source activities that were typically larger and peaked earlier than the ipsilateral activities. In addition, the ipsilateralcontralateral amplitude differences from monaural presentation were similar for left and for right ear stimulation. For unilaterally deaf subjects, the previously reported reduction in ipsilateral-contralateral amplitude differences based on scalp waveforms was also observed in the dipole source waveforms. However, analysis of the source dipole activity demonstrated that the reduced inter-hemispheric amplitude differences were ear dependent. Specifically, these changes were found only in those subjects affected by profound left ear unilateral deafness.

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“…Corresponding increases in linear dimensions are consistent with the decrease in the tonotopic gradient observed in this study. Previous estimates of the adult cortical frequency gradient range from 3 to 7 kHz/mm (Eggermont and Komiya 2000;Harrison et al 1991;Merzenich et al 1975;Rajan et al 1993;Reale and Imig 1980;Stanton and Harrison 1996). The cortical frequency gradients reported for the oldest animals in the present study are on the low end of this distribution.…”

Section: Tonotopic Gradientmentioning

confidence: 99%

Spatial Organization of Frequency Response Areas and Rate/Level Functions in the Developing AI

Bonham

Cheung²,

Godey³

et al. 2004

Journal of Neurophysiology

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. Spatial organization of frequency response areas and rate/level functions in the developing AI. J Neurophysiol 91: 841-854, 2004. First published October 8, 2003 10.1152/jn.00017.2003. The current study was conducted to extend our understanding of changes in spatial organization and response properties of cortical neurons in the developing mammalian forebrain. Extracellular multiunit responses to tones were recorded from a dense array of penetrations covering entire isofrequency contours in the primary auditory cortex (AI) of pentobarbital anesthetized kittens. Ages ranged from postnatal day 14 (P14), shortly after acquisition of normal auditory response thresholds, through postnatal day 111 (P111), when the kittens were largely mature. Spatial organization of the AI was tonotopically ordered by P14. The tonotopic gradient decreased with chronological maturation. At P14 the gradient was about 3.5 kHz/mm. By P111 it had declined to about 2.5 kHz/mm, so that the cortical region encompassing a fixed 3-to 15-kHz frequency range enlarged along its posterior-anterior dimension. Response properties of developing AI neurons changed in both frequency selectivity and intensity selectivity. The mean frequency tuning bandwidth increased with age. Initially, tuning bandwidths were narrow throughout the entire AI. With progressive maturation, broader bandwidths were observed in areas dorsal and ventral to a central region in which neurons remained narrowly tuned. The resulting spatial organization of tuning bandwidth was similar to that reported in adult cats. The majority of recording sites manifested nonmonotonic rate/level functions at all ages. However, the proportion of sites with monotonic rate/level functions increased with age. No spatial organization of rate/level functions (monotonic and nonmonotonic) was observed through P111. The relatively late development of bandwidth tuning in the AI compared with the early presence of tonotopic organization suggests that different developmental processes are responsible for structuring these two dimensions of acoustic selectivity. I N T R O D U C T I O NThe primary auditory cortex (AI) is organized topographically and reflects the spatial layout of the sensory surface (Merzenich and Brugge 1973;Reale and Imig 1980). The AI representation comprises tonotopically arrayed isofrequency domains resulting in an inhomogeneous, systematic spatial distribution of characteristic frequency (CF; i.e., the frequency of a tone burst to which a neuron is most sensitive).In the adult cat, the spatial distributions of other response parameters are also nonhomogeneous, such that neighboring locations within the AI often exhibit similar tuning bandwidths (Schreiner and Mendelson 1990) and rate/level functions (Clarey et al. 1994;Imig et al. 1990;Phillips et al. 1985Phillips et al. , 1994. Tuning bandwidths of local cell clusters in the central portion of the mature AI are sharper than bandwidths in flanking ventral and dorsal regions (Schreiner and Mendelson 1990). The spatial distribution of ...

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Reorganization of auditory cortex after neonatal high frequency cochlear hearing loss

Cited by 117 publications

References 20 publications

Perinatal anoxia degrades auditory system function in rats

Perinatal anoxia degrades auditory system function in rats

Differential Ear Effects of Profound Unilateral Deafness on the Adult Human Central Auditory System

Spatial Organization of Frequency Response Areas and Rate/Level Functions in the Developing AI

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