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International Journal of... 2020In the last years, the attention to the role of gender in physiopathology and pharmacology of diseases in several medical disciplines is rising; however, the data on the... (Review)
Review
In the last years, the attention to the role of gender in physiopathology and pharmacology of diseases in several medical disciplines is rising; however, the data on the relationship between gender and audio-vestibular disorders are still inconclusive and sometimes confusing. With this letter to the editor, we would like to review the role of gender in audio-vestibular disorders. Literature data show that anatomic variances of the inner ear do exist in men and women and that the different physiology and/or hormonal influence between genders could produce different clinical outcome of routine audiological and vestibular tests. Beyond the epidemiological gender-related differences, the clinical data suggest that the gender has a potential role as an etiopathogenetic factor in audio-vestibular disorders and it is probably responsible for the different clinical features observed between male and female subjects.
Topics: Auditory Pathways; Ear, Inner; Female; Hearing Disorders; Hearing Loss, Sensorineural; Hormones; Humans; Male; Sex Characteristics; Sex Factors; Vestibular Diseases
PubMed: 32525749
DOI: 10.1177/2058738420929174 -
Frontiers in Neural Circuits 2021Nitric oxide (NO) is of fundamental importance in regulating immune, cardiovascular, reproductive, neuromuscular, and nervous system function. It is rapidly synthesized... (Review)
Review
Nitric oxide (NO) is of fundamental importance in regulating immune, cardiovascular, reproductive, neuromuscular, and nervous system function. It is rapidly synthesized and cannot be confined, it is highly reactive, so its lifetime is measured in seconds. These distinctive properties (contrasting with classical neurotransmitters and neuromodulators) give rise to the concept of NO as a "volume transmitter," where it is generated from an active source, diffuses to interact with proteins and receptors within a sphere of influence or volume, but limited in distance and time by its short half-life. In the auditory system, the neuronal NO-synthetizing enzyme, nNOS, is highly expressed and tightly coupled to postsynaptic calcium influx at excitatory synapses. This provides a powerful activity-dependent control of postsynaptic intrinsic excitability via cGMP generation, protein kinase G activation and modulation of voltage-gated conductances. NO may also regulate vesicle mobility via retrograde signaling. This Mini Review focuses on the auditory system, but highlights general mechanisms by which NO mediates neuronal intrinsic plasticity and synaptic transmission. The dependence of NO generation on synaptic and sound-evoked activity has important local modulatory actions and NO serves as a "volume transmitter" in the auditory brainstem. It also has potentially destructive consequences during intense activity or on spill-over from other NO sources during pathological conditions, when aberrant signaling may interfere with the precisely timed and tonotopically organized auditory system.
Topics: Auditory Pathways; Nitric Oxide; Signal Transduction; Synapses; Synaptic Transmission
PubMed: 34712124
DOI: 10.3389/fncir.2021.759342 -
Hearing Research Mar 2023To generate insight from experimental data, it is critical to understand the inter-relationships between individual data points and place them in context within a... (Review)
Review
To generate insight from experimental data, it is critical to understand the inter-relationships between individual data points and place them in context within a structured framework. Quantitative modeling can provide the scaffolding for such an endeavor. Our main objective in this review is to provide a primer on the range of quantitative tools available to experimental auditory neuroscientists. Quantitative modeling is advantageous because it can provide a compact summary of observed data, make underlying assumptions explicit, and generate predictions for future experiments. Quantitative models may be developed to characterize or fit observed data, to test theories of how a task may be solved by neural circuits, to determine how observed biophysical details might contribute to measured activity patterns, or to predict how an experimental manipulation would affect neural activity. In complexity, quantitative models can range from those that are highly biophysically realistic and that include detailed simulations at the level of individual synapses, to those that use abstract and simplified neuron models to simulate entire networks. Here, we survey the landscape of recently developed models of auditory cortical processing, highlighting a small selection of models to demonstrate how they help generate insight into the mechanisms of auditory processing. We discuss examples ranging from models that use details of synaptic properties to explain the temporal pattern of cortical responses to those that use modern deep neural networks to gain insight into human fMRI data. We conclude by discussing a biologically realistic and interpretable model that our laboratory has developed to explore aspects of vocalization categorization in the auditory pathway.
Topics: Humans; Auditory Cortex; Acoustic Stimulation; Auditory Perception; Auditory Pathways; Neural Networks, Computer; Models, Neurological
PubMed: 36696724
DOI: 10.1016/j.heares.2023.108697 -
Handbook of Clinical Neurology 2015Music is a complex acoustic signal that relies on a number of different brain and cognitive processes to create the sensation of hearing. Changes in hearing function are... (Review)
Review
Music is a complex acoustic signal that relies on a number of different brain and cognitive processes to create the sensation of hearing. Changes in hearing function are generally not a major focus of concern for persons with a majority of neurodegenerative diseases associated with dementia, such as Alzheimer disease (AD). However, changes in the processing of sounds may be an early, and possibly preclinical, feature of AD and other neurodegenerative diseases. The aim of this chapter is to review the current state of knowledge concerning hearing and music perception in persons who have a dementia as a result of a neurodegenerative disease. The review focuses on both peripheral and central auditory processing in common neurodegenerative diseases, with a particular focus on the processing of music and other non-verbal sounds. The chapter also reviews music interventions used for persons with neurodegenerative diseases.
Topics: Auditory Pathways; Auditory Perceptual Disorders; Dementia; Hearing Disorders; Humans; Music
PubMed: 25726296
DOI: 10.1016/B978-0-444-62630-1.00037-8 -
Handbook of Clinical Neurology 2015Auditory development involves changes in the peripheral and central nervous system along the auditory pathways, and these occur naturally, and in response to... (Review)
Review
Auditory development involves changes in the peripheral and central nervous system along the auditory pathways, and these occur naturally, and in response to stimulation. Human development occurs along a trajectory that can last decades, and is studied using behavioral psychophysics, as well as physiologic measurements with neural imaging. The auditory system constructs a perceptual space that takes information from objects and groups, segregates sounds, and provides meaning and access to communication tools such as language. Auditory signals are processed in a series of analysis stages, from peripheral to central. Coding of information has been studied for features of sound, including frequency, intensity, loudness, and location, in quiet and in the presence of maskers. In the latter case, the ability of the auditory system to perform an analysis of the scene becomes highly relevant. While some basic abilities are well developed at birth, there is a clear prolonged maturation of auditory development well into the teenage years. Maturation involves auditory pathways. However, non-auditory changes (attention, memory, cognition) play an important role in auditory development. The ability of the auditory system to adapt in response to novel stimuli is a key feature of development throughout the nervous system, known as neural plasticity.
Topics: Acoustic Stimulation; Animals; Auditory Pathways; Auditory Perception; Hearing; Humans; Psychoacoustics
PubMed: 25726262
DOI: 10.1016/B978-0-444-62630-1.00003-2 -
Predictive coding and stochastic resonance as fundamental principles of auditory phantom perception.Brain : a Journal of Neurology Dec 2023Mechanistic insight is achieved only when experiments are employed to test formal or computational models. Furthermore, in analogy to lesion studies, phantom perception... (Review)
Review
Mechanistic insight is achieved only when experiments are employed to test formal or computational models. Furthermore, in analogy to lesion studies, phantom perception may serve as a vehicle to understand the fundamental processing principles underlying healthy auditory perception. With a special focus on tinnitus-as the prime example of auditory phantom perception-we review recent work at the intersection of artificial intelligence, psychology and neuroscience. In particular, we discuss why everyone with tinnitus suffers from (at least hidden) hearing loss, but not everyone with hearing loss suffers from tinnitus. We argue that intrinsic neural noise is generated and amplified along the auditory pathway as a compensatory mechanism to restore normal hearing based on adaptive stochastic resonance. The neural noise increase can then be misinterpreted as auditory input and perceived as tinnitus. This mechanism can be formalized in the Bayesian brain framework, where the percept (posterior) assimilates a prior prediction (brain's expectations) and likelihood (bottom-up neural signal). A higher mean and lower variance (i.e. enhanced precision) of the likelihood shifts the posterior, evincing a misinterpretation of sensory evidence, which may be further confounded by plastic changes in the brain that underwrite prior predictions. Hence, two fundamental processing principles provide the most explanatory power for the emergence of auditory phantom perceptions: predictive coding as a top-down and adaptive stochastic resonance as a complementary bottom-up mechanism. We conclude that both principles also play a crucial role in healthy auditory perception. Finally, in the context of neuroscience-inspired artificial intelligence, both processing principles may serve to improve contemporary machine learning techniques.
Topics: Humans; Tinnitus; Bayes Theorem; Artificial Intelligence; Auditory Perception; Hearing Loss; Auditory Pathways
PubMed: 37503725
DOI: 10.1093/brain/awad255 -
Annual Review of Neuroscience Jul 2016One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs).... (Review)
Review
One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.
Topics: Animals; Auditory Cortex; Auditory Pathways; Behavior; Brain Mapping; Humans; Magnetic Resonance Imaging; Nerve Net
PubMed: 27145914
DOI: 10.1146/annurev-neuro-070815-014045 -
Advances in Experimental Medicine and... 2016The fundamental problem in audition is determining the mechanisms required by the brain to transform an unlabelled mixture of auditory stimuli into coherent perceptual... (Review)
Review
The fundamental problem in audition is determining the mechanisms required by the brain to transform an unlabelled mixture of auditory stimuli into coherent perceptual representations. This process is called auditory-scene analysis. The perceptual representations that result from auditory-scene analysis are formed through a complex interaction of perceptual grouping, attention, categorization and decision-making. Despite a great deal of scientific energy devoted to understanding these aspects of hearing, we still do not understand (1) how sound perception arises from neural activity and (2) the causal relationship between neural activity and sound perception. Here, we review the role of the "ventral" auditory pathway in sound perception. We hypothesize that, in the early parts of the auditory cortex, neural activity reflects the auditory properties of a stimulus. However, in latter parts of the auditory cortex, neurons encode the sensory evidence that forms an auditory decision and are causally involved in the decision process. Finally, in the prefrontal cortex, which receives input from the auditory cortex, neural activity reflects the actual perceptual decision. Together, these studies indicate that the ventral pathway contains hierarchical circuits that are specialized for auditory perception and scene analysis.
Topics: Acoustic Stimulation; Auditory Cortex; Auditory Pathways; Auditory Perception; Humans; Sound
PubMed: 27080679
DOI: 10.1007/978-3-319-25474-6_40 -
PloS One 2021This study aimed to look for a possible relationship between thyrotropin (TSH) values from neonatal bloodspot screening testing and newborn lower auditory pathway...
OBJECTIVE
This study aimed to look for a possible relationship between thyrotropin (TSH) values from neonatal bloodspot screening testing and newborn lower auditory pathway myelinization evaluated using the brainstem evoked response audiometry (ABR) test.
METHODS
Sixty-two healthy full-term newborns without perinatal problems were enrolled in the study. TSH results were collected from neonatal bloodspot screening data and were below the test cut-off level (15μUI/mL). The TSH test was performed between three and seven days, and the ABR test was performed in the first 28 days of life. The newborns were divided into two groups: Group 1 (n = 35), TSH between 0 and 5μUI/mL, and group 2 (n = 27), TSH between 5 and 15μUI/mL. Data are presented as mean ± SD, median, or percentage, depending on the variable.
RESULTS
Wave latency and interpeak interval values for Groups 1 and 2 were as follows: Wave I: 1.8 ± 0.1 and 1.7 ± 0.1; Wave III: 4.4 ± 0.1 and 4.4 ± 0.1; Wave V: 6.9 ± 0.1 and 6.9 ± 0.1; interval I-III: 2.6 ± 0.1 and 2.6 ± 0.1; interval I-V: 5.1 ± 0.1 and 5.1 ± 0.1; interval III-V: 2.4 ± 0.1 and 2.4 ± 0.1. There were no significant differences in ABR parameters between groups 1 and 2 (p > 0.05). Multiple regression analysis showed a slight significant negative correlation between TSH and wave I values (standardized β = -0.267; p = 0.036), without observing any relationship with the other ABR waves recorded.
CONCLUSIONS
This study investigated the relationship of TSH and auditory myelinization evaluated by ABR. It did not show a significant change in lower auditory pathway myelinization according to TSH levels in newborns with TSH screening levels lower than 15 μUI/mL.
Topics: Adult; Audiometry, Evoked Response; Auditory Pathways; Congenital Hypothyroidism; Cross-Sectional Studies; Female; Humans; Infant, Newborn; Male; Thyrotropin
PubMed: 34133461
DOI: 10.1371/journal.pone.0253229 -
Developmental Dynamics : An Official... Jan 2023Acoustic communication relies crucially on accurate interpretation of information about the intensity, frequency, timing, and location of diverse sound stimuli in the... (Review)
Review
Acoustic communication relies crucially on accurate interpretation of information about the intensity, frequency, timing, and location of diverse sound stimuli in the environment. To meet this demand, neurons along different levels of the auditory system form precisely organized neural circuits. The assembly of these precise circuits requires tight regulation and coordination of multiple developmental processes. Several groups of axon guidance molecules have proven critical in controlling these processes. Among them, the family of Eph receptors and their ephrin ligands emerge as one group of key players. They mediate diverse functions at multiple levels of the auditory pathway, including axon guidance and targeting, topographic map formation, as well as cell migration and tissue pattern formation. Here, we review our current knowledge of how Eph and ephrin molecules regulate different processes in the development and maturation of central auditory circuits.
Topics: Ephrins; Auditory Pathways; Neurons; Receptors, Eph Family; Signal Transduction
PubMed: 35705527
DOI: 10.1002/dvdy.506