Synaptic Integration in Auditory Cortex

Wehr, Michael; Metherate, Raju

doi:10.1007/978-1-4419-0074-6_11

Cited by 5 publications

(6 citation statements)

References 146 publications

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“…Comparison with studies describing the effects of GABA antagonists on ACx tuning curves It has long been proposed that GABAergic inhibition sculpts ACx receptive fields (for review, see Suga, 1995;Wehr and Metherate, 2011;Yuan et al, 2011). The concept of lateral inhibition was initially promoted by the two-tone suppression (or forward masking) protocol (Brosch and Schreiner, 1997), but direct evidence only emerged when it was shown that iontophoretic application of bicuculline expands the frequency tuning curves of ACx neurons (Wang et al, 2000(Wang et al, , 2002but see Kurt et al, 2006).…”

Section: Methodological Considerationsmentioning

confidence: 99%

Cortical Inhibition Reduces Information Redundancy at Presentation of Communication Sounds in the Primary Auditory Cortex

Gaucher

Huetz

Gourévitch

et al. 2013

Journal of Neuroscience

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In all sensory modalities, intracortical inhibition shapes the functional properties of cortical neurons but also influences the responses to natural stimuli. Studies performed in various species have revealed that auditory cortex neurons respond to conspecific vocalizations by temporal spike patterns displaying a high trial-to-trial reliability, which might result from precise timing between excitation and inhibition. Studying the guinea pig auditory cortex, we show that partial blockage of GABA A receptors by gabazine (GBZ) application (10 M, a concentration that promotes expansion of cortical receptive fields) increased the evoked firing rate and the spike-timing reliability during presentation of communication sounds (conspecific and heterospecific vocalizations), whereas GABA B receptor antagonists [10 M saclofen; 10 -50 M CGP55845 (p-3-aminopropyl-p-diethoxymethyl phosphoric acid)] had nonsignificant effects. Computing mutual information (MI) from the responses to vocalizations using either the evoked firing rate or the temporal spike patterns revealed that GBZ application increased the MI derived from the activity of single cortical site but did not change the MI derived from population activity. In addition, quantification of information redundancy showed that GBZ significantly increased redundancy at the population level. This result suggests that a potential role of intracortical inhibition is to reduce information redundancy during the processing of natural stimuli.

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Section: Methodological Considerationsmentioning

confidence: 99%

Cortical Inhibition Reduces Information Redundancy at Presentation of Communication Sounds in the Primary Auditory Cortex

Gaucher

Huetz

Gourévitch

et al. 2013

Journal of Neuroscience

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“…In normal function, nonmonotonic intensity coding is generated from inhibitory mechanisms in the central auditory system (Wehr and Metherate 2011;Wehr and Zador 2003;Wu et al 2006;Zhou et al 2012). Furthermore, inhibition has been implicated as a mechanism for generating offset responses in the auditory pathway (Kopp-Scheinpflug et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Age-related changes in sound onset and offset intensity coding in auditory cortical fields A1 and CL of rhesus macaques

Ramamurthy

Recanzone

2020

Journal of Neurophysiology

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Inhibition plays a key role in shaping sensory processing in the central auditory system and has been implicated in sculpting receptive field properties such as sound intensity coding and also in shaping temporal patterns of neuronal firing such as onset- or offset-evoked responses. There is substantial evidence supporting a decrease in inhibition throughout the ascending auditory pathway in geriatric animals. We therefore examined intensity coding of onset (ON) and offset (OFF) responses in auditory cortex of aged and young monkeys. A large proportion of cells in the primary auditory cortex (A1) and the caudolateral field (CL) displayed nonmonotonic rate-level functions for OFF responses in addition to nonmonotonic coding of ON responses. Aging differentially affected ON and OFF responses; the magnitude of effects was generally greater for ON responses. In addition to higher firing rates, neurons in old monkeys exhibited a significant increase in the proportion of monotonic rate-level functions and had higher best intensities than those in young monkeys. OFF responses in young monkeys displayed a range of intensity coding relationships with ON responses of the same cells, ranging from highly similar to highly dissimilar. Dissimilarity in ON/OFF coding was greater in CL and was reduced with aging, which was largely explained by a preferential decrease in the percentage of cells with nonmonotonic coding of ON and OFF responses. The changes we observed are consistent with previously demonstrated alterations in inhibition in the ascending auditory pathway of primates and could be involved in age-related deficits in the temporal processing of sounds. NEW & NOTEWORTHY Aging has a major impact on intensity coding of neurons in auditory cortex of rhesus macaques. Neural responses to sound onset and offset were affected to different extents, and their rate-level functions became more mutually similar, which could be accounted for by the loss of nonmonotonic intensity coding in geriatric monkeys. These findings were consistent with weakened inhibition in the central auditory system and could contribute to auditory processing deficits in elderly subjects.

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“…The medial geniculate body (or nucleus, MGB) is the major source of subcortical input to the auditory cortex (AC) (for review, see Rouiller, ; Malmierca and Merchán, ; Budinger and Scheich, ; Winer, ); thus, the neuronal spectrotemporal response properties of auditory cortical neurons depend highly on their thalamocortical (TC) connectivities (for recent reviews, see Banks and Smith, ; Eggermont and Wang, ; Schreiner et al, ; Wehr and Metherate, ). Previous studies on the anatomy of the TC system in different mammalian species revealed a complex system of connections mainly determined by their source of origin, i.e., the various divisions and subdivisions of the MGB, and their cortical targets, i.e., the different layers of the diverse fields of the AC (gerbil: Budinger et al, ; mouse: Hofstetter and Ehret, ; Llano and Sherman, ; Hackett et al, ; rat: Roger and Arnault, ; Arnault and Roger, ; Winer et al, ; Kimura et al, ; Storace et al, ; Smith et al, ; guinea pig: Redies et al, ; rabbit: Velenovsky et al, ; cat: Imig and Morel, ; Mitani et al, ; Morel and Imig, ; Winer and Larue, ; Rouiller et al, ; Huang and Winer, ; Lee and Winer, ; Read et al, ; monkey: Aitkin et al, ; Luethke et al, ; Morel et al, ; Molinari et al, ; de la Mothe et al, ; Hackett et al, ).…”

mentioning

confidence: 99%

“…522:2397-2430, 2014. INDEXING TERMS: auditory cortex; medial geniculate body; Nissl; rodent; tonotopy The medial geniculate body (or nucleus, MGB) is the major source of subcortical input to the auditory cortex (AC) (for review, see Rouiller, 1997;Malmierca and Merch an, 2004;Budinger and Scheich, 2009;Winer, 2011); thus, the neuronal spectrotemporal response properties of auditory cortical neurons depend highly on their thalamocortical (TC) connectivities (for recent reviews, see Banks and Smith, 2011;Eggermont and Wang, 2011;Schreiner et al, 2011;Wehr and Metherate, 2011). Previous studies on the anatomy of the TC system in different mammalian species revealed a complex system of connections mainly determined by their source of origin, i.e., the various divisions and subdivisions of the MGB, and their cortical targets, i.e., the different layers of the diverse fields of the AC (gerbil: Budinger et al, 2000b;mouse: Hofstetter and Ehret, and Winer, 2000;Lee and Winer, 2008;Read et al, 2008;monkey: Aitkin et al, 1988;Luethke et al, 1989;Morel et al, 1993;Molinari et al, 1995;de la Mothe et al, 2006;Hackett et al, 2011a).…”

mentioning

confidence: 99%

Anatomy of the auditory thalamocortical system in the mongolian gerbil: Nuclear origins and cortical field‐, layer‐, and frequency‐specificities

Saldeitis

Happel

Ohl

et al. 2014

J of Comparative Neurology

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Knowledge of the anatomical organization of the auditory thalamocortical (TC) system is fundamental for the understanding of auditory information processing in the brain. In the Mongolian gerbil (Meriones unguiculatus), a valuable model species in auditory research, the detailed anatomy of this system has not yet been worked out in detail. Here, we investigated the projections from the three subnuclei of the medial geniculate body (MGB), namely, its ventral (MGv), dorsal (MGd), and medial (MGm) divisions, as well as from several of their subdivisions (MGv: pars lateralis [LV], pars ovoidea [OV], rostral pole [RP]; MGd: deep dorsal nucleus [DD]), to the auditory cortex (AC) by stereotaxic pressure injections and electrophysiologically guided iontophoretic injections of the anterograde tract tracer biocytin. Our data reveal highly specific features of the TC connections regarding their nuclear origin in the subdivisions of the MGB and their termination patterns in the auditory cortical fields and layers. In addition to tonotopically organized projections, primarily of the LV, OV, and DD to the AC, a large number of axons diverge across the tonotopic gradient. These originate mainly from the RP, MGd (proper), and MGm. In particular, neurons of the MGm project in a columnar fashion to several auditory fields, forming small‐ and medium‐sized boutons, and also hitherto unknown giant terminals. The distinctive layer‐specific distribution of axonal endings within the AC indicates that each of the TC connectivity systems has a specific function in auditory cortical processing. J. Comp. Neurol. 522:2397–2430, 2014. © 2014 Wiley Periodicals, Inc.

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Synaptic Integration in Auditory Cortex

Cited by 5 publications

References 146 publications

Cortical Inhibition Reduces Information Redundancy at Presentation of Communication Sounds in the Primary Auditory Cortex

Cortical Inhibition Reduces Information Redundancy at Presentation of Communication Sounds in the Primary Auditory Cortex

Age-related changes in sound onset and offset intensity coding in auditory cortical fields A1 and CL of rhesus macaques

Anatomy of the auditory thalamocortical system in the mongolian gerbil: Nuclear origins and cortical field‐, layer‐, and frequency‐specificities

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