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1.
Nat Commun ; 10(1): 5684, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831751

RESUMO

We experience the world through multiple senses simultaneously. To better understand mechanisms of multisensory processing we ask whether inputs from two senses (auditory and visual) can interact and drive plasticity in neural-circuits of the primary visual cortex (V1). Using genetically-encoded voltage and calcium indicators, we find coincident audio-visual experience modifies both the supra and subthreshold response properties of neurons in L2/3 of mouse V1. Specifically, we find that after audio-visual pairing, a subset of multimodal neurons develops enhanced auditory responses to the paired auditory stimulus. This cross-modal plasticity persists over days and is reflected in the strengthening of small functional networks of L2/3 neurons. We find V1 processes coincident auditory and visual events by strengthening functional associations between feature specific assemblies of multimodal neurons during bouts of sensory driven co-activity, leaving a trace of multisensory experience in the cortical network.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Rede Nervosa/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Animais , Camundongos , Modelos Animais , Modelos Biológicos , Plasticidade Neuronal , Neurônios/fisiologia , Estimulação Luminosa , Privação Sensorial/fisiologia
2.
PLoS Comput Biol ; 15(10): e1007430, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31626624

RESUMO

Perception of vocalizations and other behaviorally relevant sounds requires integrating acoustic information over hundreds of milliseconds. Sound-evoked activity in auditory cortex typically has much shorter latency, but the acoustic context, i.e., sound history, can modulate sound evoked activity over longer periods. Contextual effects are attributed to modulatory phenomena, such as stimulus-specific adaption and contrast gain control. However, an encoding model that links context to natural sound processing has yet to be established. We tested whether a model in which spectrally tuned inputs undergo adaptation mimicking short-term synaptic plasticity (STP) can account for contextual effects during natural sound processing. Single-unit activity was recorded from primary auditory cortex of awake ferrets during presentation of noise with natural temporal dynamics and fully natural sounds. Encoding properties were characterized by a standard linear-nonlinear spectro-temporal receptive field (LN) model and variants that incorporated STP-like adaptation. In the adapting models, STP was applied either globally across all input spectral channels or locally to subsets of channels. For most neurons, models incorporating local STP predicted neural activity as well or better than LN and global STP models. The strength of nonlinear adaptation varied across neurons. Within neurons, adaptation was generally stronger for spectral channels with excitatory than inhibitory gain. Neurons showing improved STP model performance also tended to undergo stimulus-specific adaptation, suggesting a common mechanism for these phenomena. When STP models were compared between passive and active behavior conditions, response gain often changed, but average STP parameters were stable. Thus, spectrally and temporally heterogeneous adaptation, subserved by a mechanism with STP-like dynamics, may support representation of the complex spectro-temporal patterns that comprise natural sounds across wide-ranging sensory contexts.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Estimulação Acústica , Potenciais de Ação/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Feminino , Furões , Masculino , Modelos Neurológicos , Modelos de Interação Espacial , Plasticidade Neuronal , Neurônios/fisiologia , Ruído , Som
3.
Artigo em Chinês | MEDLINE | ID: mdl-31550769

RESUMO

Acid-sensing ion channels are a class of extracellular H(+) activated cation channels, belonging to the amiloride-sensitive epithelial Na(+) channel/degenerin (ENaC/DEG) superfamily. During extracellular acidification, the channels are activated and produce corresponding action potential. Acid-sensing ion channels are extensively expressed in the peripheral and central nervous system. It plays an important in synaptic plasticity, mechanical sensation, injury sensation related to acidosis of local tissues, acid reception and retinal regulation. This article reviews the expression, biological characteristics and functions of acid-sensing ion channels in cochlea, vestibular tissue and auditory center, so as to improve the understanding of physiology and pathophysiology of auditory system.


Assuntos
Canais Iônicos Sensíveis a Ácido , Córtex Auditivo , Cóclea , Vestíbulo do Labirinto , Canais Iônicos Sensíveis a Ácido/genética , Canais Iônicos Sensíveis a Ácido/metabolismo , Córtex Auditivo/fisiologia , Cóclea/fisiologia , Humanos , Sensação , Vestíbulo do Labirinto/fisiologia
4.
Nat Commun ; 10(1): 3958, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477711

RESUMO

Despite well-established anatomical differences between primary and non-primary auditory cortex, the associated representational transformations have remained elusive. Here we show that primary and non-primary auditory cortex are differentiated by their invariance to real-world background noise. We measured fMRI responses to natural sounds presented in isolation and in real-world noise, quantifying invariance as the correlation between the two responses for individual voxels. Non-primary areas were substantially more noise-invariant than primary areas. This primary-nonprimary difference occurred both for speech and non-speech sounds and was unaffected by a concurrent demanding visual task, suggesting that the observed invariance is not specific to speech processing and is robust to inattention. The difference was most pronounced for real-world background noise-both primary and non-primary areas were relatively robust to simple types of synthetic noise. Our results suggest a general representational transformation between auditory cortical stages, illustrating a representational consequence of hierarchical organization in the auditory system.


Assuntos
Estimulação Acústica/métodos , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Ruído , Fala/fisiologia , Adulto , Córtex Auditivo/diagnóstico por imagem , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Som , Adulto Jovem
5.
PLoS Comput Biol ; 15(9): e1006698, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31557151

RESUMO

Although information theoretic approaches have been used extensively in the analysis of the neural code, they have yet to be used to describe how information is accumulated in time while sensory systems are categorizing dynamic sensory stimuli such as speech sounds or visual objects. Here, we present a novel method to estimate the cumulative information for stimuli or categories. We further define a time-varying categorical information index that, by comparing the information obtained for stimuli versus categories of these same stimuli, quantifies invariant neural representations. We use these methods to investigate the dynamic properties of avian cortical auditory neurons recorded in zebra finches that were listening to a large set of call stimuli sampled from the complete vocal repertoire of this species. We found that the time-varying rates carry 5 times more information than the mean firing rates even in the first 100 ms. We also found that cumulative information has slow time constants (100-600 ms) relative to the typical integration time of single neurons, reflecting the fact that the behaviorally informative features of auditory objects are time-varying sound patterns. When we correlated firing rates and information values, we found that average information correlates with average firing rate but that higher-rates found at the onset response yielded similar information values as the lower-rates found in the sustained response: the onset and sustained response of avian cortical auditory neurons provide similar levels of independent information about call identity and call-type. Finally, our information measures allowed us to rigorously define categorical neurons; these categorical neurons show a high degree of invariance for vocalizations within a call-type. Peak invariance is found around 150 ms after stimulus onset. Surprisingly, call-type invariant neurons were found in both primary and secondary avian auditory areas.


Assuntos
Córtex Auditivo , Modelos Neurológicos , Neurônios/fisiologia , Vocalização Animal/fisiologia , Estimulação Acústica , Animais , Córtex Auditivo/citologia , Córtex Auditivo/fisiologia , Biologia Computacional , Feminino , Tentilhões/fisiologia , Masculino
6.
Nat Commun ; 10(1): 3440, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371713

RESUMO

Prior experience enables the formation of expectations of upcoming sensory events. However, in the auditory modality, it is not known whether prediction-related neural signals carry feature-specific information. Here, using magnetoencephalography (MEG), we examined whether predictions of future auditory stimuli carry tonotopic specific information. Participants passively listened to sound sequences of four carrier frequencies (tones) with a fixed presentation rate, ensuring strong temporal expectations of when the next stimulus would occur. Expectation of which frequency would occur was parametrically modulated across the sequences, and sounds were occasionally omitted. We show that increasing the regularity of the sequence boosts carrier-frequency-specific neural activity patterns during both the anticipatory and omission periods, indicating that prediction-related neural activity is indeed feature-specific. Our results illustrate that even without bottom-up input, auditory predictions can activate tonotopically specific templates.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Magnetoencefalografia , Masculino , Análise Multivariada , Projetos de Pesquisa , Som , Voluntários , Adulto Jovem
7.
Nat Commun ; 10(1): 3671, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31413319

RESUMO

Being able to produce sounds that capture attention and elicit rapid reactions is the prime goal of communication. One strategy, exploited by alarm signals, consists in emitting fast but perceptible amplitude modulations in the roughness range (30-150 Hz). Here, we investigate the perceptual and neural mechanisms underlying aversion to such temporally salient sounds. By measuring subjective aversion to repetitive acoustic transients, we identify a nonlinear pattern of aversion restricted to the roughness range. Using human intracranial recordings, we show that rough sounds do not merely affect local auditory processes but instead synchronise large-scale, supramodal, salience-related networks in a steady-state, sustained manner. Rough sounds synchronise activity throughout superior temporal regions, subcortical and cortical limbic areas, and the frontal cortex, a network classically involved in aversion processing. This pattern correlates with subjective aversion in all these regions, consistent with the hypothesis that roughness enhances auditory aversion through spreading of neural synchronisation.


Assuntos
Atenção , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Som , Estimulação Acústica , Acústica , Adolescente , Adulto , Vias Auditivas/fisiologia , Epilepsia Resistente a Medicamentos/cirurgia , Eletrocorticografia , Epilepsias Parciais/cirurgia , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
8.
Nat Neurosci ; 22(9): 1469-1476, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31406364

RESUMO

Vocal learners use early social experience to develop auditory skills specialized for communication. However, it is unknown where in the auditory pathway neural responses become selective for vocalizations or how the underlying encoding mechanisms change with experience. We used a vocal tutoring manipulation in two species of songbird to reveal that tuning for conspecific song arises within the primary auditory cortical circuit. Neurons in the deep region of primary auditory cortex responded more to conspecific songs than to other species' songs and more to species-typical spectrotemporal modulations, but neurons in the intermediate (thalamorecipient) region did not. Moreover, birds that learned song from another species exhibited parallel shifts in selectivity and tuning toward the tutor species' songs in the deep but not the intermediate region. Our results locate a region in the auditory processing hierarchy where an experience-dependent coding mechanism aligns auditory responses with the output of a learned vocal motor behavior.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Aprendizagem/fisiologia , Vocalização Animal/fisiologia , Animais , Percepção Auditiva/fisiologia , Tentilhões/fisiologia , Neurônios/fisiologia
9.
Brain Struct Funct ; 224(8): 2907-2924, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31456067

RESUMO

Empirical evidence suggests that, in the auditory cortex (AC), the phase relationship between spikes and local-field potentials (LFPs) plays an important role in the processing of auditory stimuli. Nevertheless, unlike the case of other sensory systems, it remains largely unexplored in the auditory modality whether the properties of the cortical columnar microcircuit shape the dynamics of spike-LFP coherence in a layer-specific manner. In this study, we directly tackle this issue by addressing whether spike-LFP and LFP-stimulus phase synchronization are spatially distributed in the AC during sensory processing, by performing laminar recordings in the cortex of awake short-tailed bats (Carollia perspicillata) while animals listened to conspecific distress vocalizations. We show that, in the AC, spike-LFP and LFP-stimulus synchrony depend significantly on cortical depth, and that sensory stimulation alters the spatial and spectral patterns of spike-LFP phase-locking. We argue that such laminar distribution of coherence could have functional implications for the representation of naturalistic auditory stimuli at a cortical level.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Ondas Encefálicas , Quirópteros/fisiologia , Neurônios/fisiologia , Estimulação Acústica , Potenciais de Ação , Animais , Sincronização Cortical , Ritmo Delta , Masculino , Ritmo Teta , Vocalização Animal
10.
Brain Struct Funct ; 224(8): 2925-2937, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31468120

RESUMO

Neuroimaging studies have demonstrated that mental imagery and perception share similar neural substrates, however, there are still ambiguities according to different auditory imagery content. In addition, there is still a lack of information regarding the underlying neural correlation between the two modalities. In the present study, we adopted functional magnetic resonance imaging to explore the neural representation during imagery and perception of actual sounds in our surroundings. Univariate analysis was used to assess the differences between the modalities of average activation intensity, and stronger imagery activation was found in sensorimotor regions but weaker activation in auditory association cortices. Additionally, multi-voxel pattern analysis with a support vector machine classifier was implemented to decode environmental sounds within- or cross-modality. Significant above-chance accuracies were found in all overlapping regions in the classification of within-modality, while successful cross-modality classification only was found in sensorimotor regions. Both univariate and multivariate analyses found distinct representation between auditory imagery and perception in the overlapping regions, including superior temporal gyrus and inferior frontal sulcus as well as the precentral cortex and pre-supplementary motor area. Our results confirm the overlapping activation regions between auditory imagery and perception reported by previous studies and suggest that activation regions showed dissociable representation pattern in imagery and perception of sound categories.


Assuntos
Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Imaginação/fisiologia , Estimulação Acústica , Adulto , Córtex Auditivo/fisiologia , Mapeamento Encefálico , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Som , Adulto Jovem
11.
PLoS Biol ; 17(8): e3000417, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31469831

RESUMO

Threatening sounds can elicit a series of defensive behavioral reactions in animals for survival, but the underlying neural substrates are not fully understood. Here, we demonstrate a previously unexplored neural pathway in mice that projects directly from the auditory cortex (ACx) to the lateral periaqueductal gray (lPAG) and controls noise-evoked defensive behaviors. Electrophysiological recordings showed that the lPAG could be excited by a loud noise that induced an escape-like behavior. Trans-synaptic viral tracing showed that a great number of glutamatergic neurons, rather than GABAergic neurons, in the lPAG were directly innervated by those in layer V of the ACx. Activation of this pathway by optogenetic manipulations produced a behavior in mice that mimicked the noise-evoked escape, whereas inhibition of the pathway reduced this behavior. Therefore, our newly identified descending pathway is a novel neural substrate for noise-evoked escape and is involved in controlling the threat-related behavior.


Assuntos
Córtex Auditivo/fisiologia , Reação de Fuga/fisiologia , Substância Cinzenta Periaquedutal/metabolismo , Animais , Córtex Auditivo/metabolismo , Percepção Auditiva/fisiologia , Comportamento Animal/fisiologia , Mecanismos de Defesa , Aminoácidos Excitatórios/fisiologia , Neurônios GABAérgicos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Optogenética/métodos , Substância Cinzenta Periaquedutal/fisiologia , Som
12.
Nat Hum Behav ; 3(9): 974-987, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31285622

RESUMO

Speech is the most important signal in our auditory environment, and the processing of speech is highly dependent on context. However, it is unknown how contextual demands influence the neural encoding of speech. Here, we examine the context dependence of auditory cortical mechanisms for speech encoding at the level of the representation of fundamental acoustic features (spectrotemporal modulations) using model-based functional magnetic resonance imaging. We found that the performance of different tasks on identical speech sounds leads to neural enhancement of the acoustic features in the stimuli that are critically relevant to task performance. These task effects were observed at the earliest stages of auditory cortical processing, in line with interactive accounts of speech processing. Our work provides important insights into the mechanisms that underlie the processing of contextually relevant acoustic information within our rich and dynamic auditory environment.


Assuntos
Córtex Auditivo/fisiologia , Percepção da Fala , Estimulação Acústica , Córtex Auditivo/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Feminino , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Acústica da Fala , Percepção da Fala/fisiologia , Adulto Jovem
13.
Nat Commun ; 10(1): 3019, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289272

RESUMO

Auditory cortex is required for sound localisation, but how neural firing in auditory cortex underlies our perception of sound sources in space remains unclear. Specifically, whether neurons in auditory cortex represent spatial cues or an integrated representation of auditory space across cues is not known. Here, we measured the spatial receptive fields of neurons in primary auditory cortex (A1) while ferrets performed a relative localisation task. Manipulating the availability of binaural and spectral localisation cues had little impact on ferrets' performance, or on neural spatial tuning. A subpopulation of neurons encoded spatial position consistently across localisation cue type. Furthermore, neural firing pattern decoders outperformed two-channel model decoders using population activity. Together, these observations suggest that A1 encodes the location of sound sources, as opposed to spatial cue values.


Assuntos
Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Neurônios/fisiologia , Localização de Som/fisiologia , Estimulação Acústica/instrumentação , Estimulação Acústica/métodos , Potenciais de Ação/fisiologia , Animais , Córtex Auditivo/citologia , Comportamento Animal/fisiologia , Sinais (Psicologia) , Feminino , Furões , Microeletrodos , Modelos Animais
14.
Int J Pediatr Otorhinolaryngol ; 125: 98-102, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31276893

RESUMO

OBJECTIVES: The present study aimed to determine the relationship between aided cortical auditory evoked potentials and aided behavioral thresholds. Secondary aims of the study were to investigate the relationship between age and Cortical Auditory Evoked Potentials latencies, and to analyze the relationship between the /m/, /g/ and /t/ stimuli. METHOD: Therefore, 20 subjects (4-8 years old) who diagnosed with moderate to severe hearing loss were included in the study. Behavioral pure-tone audiometry was performed using supra-aural earphones. After verification of the settings of hearing aid settings, aided behavioral thresholds were determined in the free field. Aided CAEPs were recorded using the HEARLab system in a sound-treated room. The /m/, /g/, and /t/ speech stimuli were applied with durations of 30, 20, and 30 ms respectively. RESULTS: A strong correlation was found between aided cortical auditory evoked responses at the level of 55 dB SPL and aided behavioral thresholds in the free field(r=0.86). We showed that the CAEP latencies were not correlated with the age (/m/ stimulus [r=-0.051; p=0.830], /g/ stimulus [r=-0.053; p=0.825], and /t/ stimulus [r=0.121; p=0,610]). The mean latency of the /m/ stimulus at 55 dB SPL intensity was longer than those of the /g/ and /t/ stimuli. CONCLUSION: The results of the present study demonstrated that the use of the cortical auditory evoked potentials is clinically useful for measuring the hearing aid benefit. The CAEP can predict the aided behavioral thresholds in children with moderate hearing loss.


Assuntos
Estimulação Acústica , Córtex Auditivo/fisiologia , Limiar Auditivo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Auxiliares de Audição , Audiometria de Tons Puros , Criança , Pré-Escolar , Feminino , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Masculino
15.
Nat Commun ; 10(1): 3075, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300665

RESUMO

The brain has a remarkable capacity to adapt to changes in sensory inputs and to learn from experience. However, the neural circuits responsible for this flexible processing remain poorly understood. Using optogenetic silencing of ArchT-expressing neurons in adult ferrets, we show that within-trial activity in primary auditory cortex (A1) is required for training-dependent recovery in sound-localization accuracy following monaural deprivation. Because localization accuracy under normal-hearing conditions was unaffected, this highlights a specific role for cortical activity in learning. A1-dependent plasticity appears to leave a memory trace that can be retrieved, facilitating adaptation during a second period of monaural deprivation. However, in ferrets in which learning was initially disrupted by perturbing A1 activity, subsequent optogenetic suppression during training no longer affected localization accuracy when one ear was occluded. After the initial learning phase, the reweighting of spatial cues that primarily underpins this plasticity may therefore occur in A1 target neurons.


Assuntos
Córtex Auditivo/fisiologia , Aprendizagem/fisiologia , Localização de Som/fisiologia , Estimulação Acústica , Animais , Córtex Auditivo/citologia , Feminino , Furões , Modelos Animais , Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Optogenética
16.
Brain Struct Funct ; 224(7): 2577-2586, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31312903

RESUMO

Self-generated tones elicit smaller brain responses as compared to externally generated tones. This phenomenon known as sensory attenuation has been explained in terms of an internal forward model in which the brain predicts the upcoming events and thereby attenuates the sensory processing. Such prediction processes have been suggested to occur via an efference copy of the motor command that is sent from the motor system to the lower order sensory cortex. However, little is known about how the prediction is implemented in the brain's network organization. Because the supplementary motor area (SMA) is a primary brain structure of the motor system, we attributed the implementation of the prediction to the SMA. To address this question, we examined generative network models for auditory ERPs. ERPs were evoked by either a self-generated or externally generated tone, while subjects were paying attention to their motor action or to the tone. The tone itself was the same throughout all conditions. The network models consisted of three subsets embedding alternative hypotheses of the hierarchical structures: (1) auditory fields of the temporal lobe, (2) adding connections to the SMA, and (3) adding prediction signal to the SMA. The model comparison revealed that all ERP responses were mediated by the network connections across the auditory cortex and the SMA. Importantly, the prediction signal to the SMA was required when the tone was self-generated irrespective of the attention factor, whereas the externally generated tone did not require the prediction. We discussed these results in the context of the predictive coding framework.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Potenciais Evocados Auditivos/fisiologia , Córtex Motor/fisiologia , Estimulação Acústica/métodos , Atenção/fisiologia , Eletroencefalografia/métodos , Feminino , Audição/fisiologia , Humanos , Masculino , Desempenho Psicomotor/fisiologia
17.
J Int Adv Otol ; 15(2): 321-325, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31347512

RESUMO

There are limited treatment options for successful management of tinnitus, which is highly prevalent worldwide. The pathogenetic role of auditory cortex activation changes in tinnitus has been reported by various functional studies that suggest that the emerging neuromodulation techniques may pave way toward better treatment response. The current case report depicts the use of functional near-infrared spectroscopy (fNIRS) based on the assessment of improvement in auditory cortex functioning in chronic tinnitus by transcranial direct current stimulation (tDCS).


Assuntos
Córtex Auditivo/fisiologia , Zumbido/terapia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Humanos , Masculino , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Zumbido/fisiopatologia
18.
Brain Struct Funct ; 224(7): 2487-2504, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31280349

RESUMO

Emotional sounds are processed within a large cortico-subcortical network, of which the auditory cortex, the voice area, and the amygdala are the core regions. Using 7T fMRI, we have compared the effect of emotional valence (positive, neutral, and negative) and the effect of the type of environmental sounds (human vocalizations and non-vocalizations) on neural activity within individual early stage auditory areas, the voice area, and the amygdala. A two-way ANOVA was applied to the BOLD time course within each ROI. In several early stage auditory areas, it yielded a significant main effect of vocalizations and of valence, but not a significant interaction. Significant interaction as well as significant main effects of vocalization and of valence were present in the voice area; the former was driven by a significant emotional modulation of vocalizations but not of other sounds. Within the amygdala, only the main effect of valence was significant. Post-hoc correlation analysis highlighted coupling between the voice area and early stage auditory areas during the presentation of any vocalizations, and between the voice area and the right amygdala during positive vocalizations. Thus, the voice area is selectively devoted to the encoding of the emotional valence of vocalizations; it shares with several early stage auditory areas encoding characteristics for vocalizations and with the amygdala for the emotional modulation of vocalizations. These results are indicative of a dual pathway, whereby the emotional modulation of vocalizations within the voice area integrates the input from the lateral early stage auditory areas and from the amygdala.


Assuntos
Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Emoções/fisiologia , Voz/fisiologia , Estimulação Acústica/métodos , Adulto , Tonsila do Cerebelo/fisiologia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino
19.
Handb Clin Neurol ; 160: 465-479, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31277869

RESUMO

This chapter presents a summary of current notions regarding cortical specialization for language and a description of the methods employed for the assessment of that specialization. We distinguish between the "canonical" model of language specialization as it evolved from the early observations of Broca and Wernicke, implicating the inferior frontal gyrus and the posterior temporal cortex of the speech dominant hemisphere (usually the left) and its modern variants that are based on both detailed studies of lesion-symptom correlations and on the results of functional brain mapping methods. The latter fall into two categories. The first includes the invasive ones, namely the Wada procedure for assessing hemispheric dominance for speech and cortical stimulation mapping (whether intraoperative or extraoperative) for identifying cortical nodes or "hubs" of the neuronal network for language. The second category includes the noninvasive methods of functional magnetic resonance imaging, magnetoencephalography, and transcranial magnetic stimulation used for both assessment of hemispheric dominance for language and for localization of the cortical nodes of the language network. The advantages and the shortcomings of all methods are juxtaposed to facilitate selection of particular methods of assessment of the locus of the language network in particular cases.


Assuntos
Córtex Auditivo/fisiologia , Mapeamento Encefálico/métodos , Lateralidade Funcional/fisiologia , Linguagem , Aprendizagem por Associação/fisiologia , Córtex Cerebral/fisiologia , Humanos , Imagem por Ressonância Magnética/métodos , Estimulação Magnética Transcraniana/métodos
20.
Nat Commun ; 10(1): 2783, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31239458

RESUMO

The left hemisphere's dominance in processing social communication has been known for over a century, but the mechanisms underlying this lateralized cortical function are poorly understood. Here, we compare the structure, function, and development of each auditory cortex (ACx) in the mouse to look for specializations that may underlie lateralization. Using Fos brain volume imaging, we found greater activation in the left ACx in response to vocalizations, while the right ACx responded more to frequency sweeps. In vivo recordings identified hemispheric differences in spectrotemporal selectivity, reinforcing their functional differences. We then compared the synaptic connectivity within each hemisphere and discovered lateralized circuit-motifs that are hearing experience-dependent. Our results suggest a specialist role for the left ACx, focused on facilitating the detection of specific vocalization features, while the right ACx is a generalist with the ability to integrate spectrotemporal features more broadly.


Assuntos
Córtex Auditivo/fisiologia , Estimulação Acústica , Animais , Córtex Auditivo/diagnóstico por imagem , Percepção Auditiva , Lateralidade Funcional , Masculino , Camundongos , Camundongos Endogâmicos CBA
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