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Nodal FR, Leach ND, Keating P, Dahmen JC, Zhao D, King AJ, Bajo VM. Neural processing in the primary auditory cortex following cholinergic lesions of the basal forebrain in ferrets. Hear Res 2024; 447:109025. [PMID: 38733712 PMCID: PMC11265294 DOI: 10.1016/j.heares.2024.109025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/22/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024]
Abstract
Cortical acetylcholine (ACh) release has been linked to various cognitive functions, including perceptual learning. We have previously shown that cortical cholinergic innervation is necessary for accurate sound localization in ferrets, as well as for their ability to adapt with training to altered spatial cues. To explore whether these behavioral deficits are associated with changes in the response properties of cortical neurons, we recorded neural activity in the primary auditory cortex (A1) of anesthetized ferrets in which cholinergic inputs had been reduced by making bilateral injections of the immunotoxin ME20.4-SAP in the nucleus basalis (NB) prior to training the animals. The pattern of spontaneous activity of A1 units recorded in the ferrets with cholinergic lesions (NB ACh-) was similar to that in controls, although the proportion of burst-type units was significantly lower. Depletion of ACh also resulted in more synchronous activity in A1. No changes in thresholds, frequency tuning or in the distribution of characteristic frequencies were found in these animals. When tested with normal acoustic inputs, the spatial sensitivity of A1 neurons in the NB ACh- ferrets and the distribution of their preferred interaural level differences also closely resembled those found in control animals, indicating that these properties had not been altered by sound localization training with one ear occluded. Simulating the animals' previous experience with a virtual earplug in one ear reduced the contralateral preference of A1 units in both groups, but caused azimuth sensitivity to change in slightly different ways, which may reflect the modest adaptation observed in the NB ACh- group. These results show that while ACh is required for behavioral adaptation to altered spatial cues, it is not required for maintenance of the spectral and spatial response properties of A1 neurons.
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Affiliation(s)
- Fernando R Nodal
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom.
| | | | - Peter Keating
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, United Kingdom
| | - Johannes C Dahmen
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom
| | - Dylan Zhao
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom
| | - Andrew J King
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom
| | - Victoria M Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom
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2
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Knipper M, Singer W, Schwabe K, Hagberg GE, Li Hegner Y, Rüttiger L, Braun C, Land R. Disturbed Balance of Inhibitory Signaling Links Hearing Loss and Cognition. Front Neural Circuits 2022; 15:785603. [PMID: 35069123 PMCID: PMC8770933 DOI: 10.3389/fncir.2021.785603] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/08/2021] [Indexed: 12/19/2022] Open
Abstract
Neuronal hyperexcitability in the central auditory pathway linked to reduced inhibitory activity is associated with numerous forms of hearing loss, including noise damage, age-dependent hearing loss, and deafness, as well as tinnitus or auditory processing deficits in autism spectrum disorder (ASD). In most cases, the reduced central inhibitory activity and the accompanying hyperexcitability are interpreted as an active compensatory response to the absence of synaptic activity, linked to increased central neural gain control (increased output activity relative to reduced input). We here suggest that hyperexcitability also could be related to an immaturity or impairment of tonic inhibitory strength that typically develops in an activity-dependent process in the ascending auditory pathway with auditory experience. In these cases, high-SR auditory nerve fibers, which are critical for the shortest latencies and lowest sound thresholds, may have either not matured (possibly in congenital deafness or autism) or are dysfunctional (possibly after sudden, stressful auditory trauma or age-dependent hearing loss linked with cognitive decline). Fast auditory processing deficits can occur despite maintained basal hearing. In that case, tonic inhibitory strength is reduced in ascending auditory nuclei, and fast inhibitory parvalbumin positive interneuron (PV-IN) dendrites are diminished in auditory and frontal brain regions. This leads to deficits in central neural gain control linked to hippocampal LTP/LTD deficiencies, cognitive deficits, and unbalanced extra-hypothalamic stress control. Under these conditions, a diminished inhibitory strength may weaken local neuronal coupling to homeostatic vascular responses required for the metabolic support of auditory adjustment processes. We emphasize the need to distinguish these two states of excitatory/inhibitory imbalance in hearing disorders: (i) Under conditions of preserved fast auditory processing and sustained tonic inhibitory strength, an excitatory/inhibitory imbalance following auditory deprivation can maintain precise hearing through a memory linked, transient disinhibition that leads to enhanced spiking fidelity (central neural gain⇑) (ii) Under conditions of critically diminished fast auditory processing and reduced tonic inhibitory strength, hyperexcitability can be part of an increased synchronization over a broader frequency range, linked to reduced spiking reliability (central neural gain⇓). This latter stage mutually reinforces diminished metabolic support for auditory adjustment processes, increasing the risks for canonical dementia syndromes.
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Affiliation(s)
- Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
- *Correspondence: Marlies Knipper,
| | - Wibke Singer
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Kerstin Schwabe
- Experimental Neurosurgery, Department of Neurosurgery, Hannover Medical School, Hanover, Germany
| | - Gisela E. Hagberg
- Department of Biomedical Magnetic Resonance, University Hospital Tübingen (UKT), Tübingen, Germany
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Yiwen Li Hegner
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lukas Rüttiger
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
| | - Christoph Braun
- MEG Center, University of Tübingen, Tübingen, Germany
- Center of Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Rüdiger Land
- Department of Experimental Otology, Institute for Audioneurotechnology, Hannover Medical School, Hanover, Germany
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Long-range inputome of cortical neurons containing corticotropin-releasing hormone. Sci Rep 2020; 10:12209. [PMID: 32699360 PMCID: PMC7376058 DOI: 10.1038/s41598-020-68115-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/12/2020] [Indexed: 12/31/2022] Open
Abstract
Dissection of the neural circuits of the cerebral cortex is essential for studying mechanisms underlying brain function. Herein, combining a retrograde rabies tracing system with fluorescent micro-optical sectional tomography, we investigated long-range input neurons of corticotropin-releasing hormone containing neurons in the six main cortical areas, including the prefrontal, somatosensory, motor, auditory, and visual cortices. The whole brain distribution of input neurons showed similar patterns to input neurons distributed mainly in the adjacent cortical areas, thalamus, and basal forebrain. Reconstruction of continuous three-dimensional datasets showed the anterior and middle thalamus projected mainly to the rostral cortex whereas the posterior and lateral projected to the caudal cortex. In the basal forebrain, immunohistochemical staining showed these cortical areas received afferent information from cholinergic neurons in the substantia innominata and lateral globus pallidus, whereas cholinergic neurons in the diagonal band nucleus projected strongly to the prefrontal and visual cortex. Additionally, dense neurons in the zona incerta and ventral hippocampus were found to project to the prefrontal cortex. These results showed general patterns of cortical input circuits and unique connection patterns of each individual area, allowing for valuable comparisons among the organisation of different cortical areas and new insight into cortical functions.
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Chambers JD, Elgueda D, Fritz JB, Shamma SA, Burkitt AN, Grayden DB. Computational Neural Modeling of Auditory Cortical Receptive Fields. Front Comput Neurosci 2019; 13:28. [PMID: 31178710 PMCID: PMC6543553 DOI: 10.3389/fncom.2019.00028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/23/2019] [Indexed: 11/13/2022] Open
Abstract
Previous studies have shown that the auditory cortex can enhance the perception of behaviorally important sounds in the presence of background noise, but the mechanisms by which it does this are not yet elucidated. Rapid plasticity of spectrotemporal receptive fields (STRFs) in the primary (A1) cortical neurons is observed during behavioral tasks that require discrimination of particular sounds. This rapid task-related change is believed to be one of the processing strategies utilized by the auditory cortex to selectively attend to one stream of sound in the presence of mixed sounds. However, the mechanism by which the brain evokes this rapid plasticity in the auditory cortex remains unclear. This paper uses a neural network model to investigate how synaptic transmission within the cortical neuron network can change the receptive fields of individual neurons. A sound signal was used as input to a model of the cochlea and auditory periphery, which activated or inhibited integrate-and-fire neuron models to represent networks in the primary auditory cortex. Each neuron in the network was tuned to a different frequency. All neurons were interconnected with excitatory or inhibitory synapses of varying strengths. Action potentials in one of the model neurons were used to calculate the receptive field using reverse correlation. The results were directly compared to previously recorded electrophysiological data from ferrets performing behavioral tasks that require discrimination of particular sounds. The neural network model could reproduce complex STRFs observed experimentally through optimizing the synaptic weights in the model. The model predicts that altering synaptic drive between cortical neurons and/or bottom-up synaptic drive from the cochlear model to the cortical neurons can account for rapid task-related changes observed experimentally in A1 neurons. By identifying changes in the synaptic drive during behavioral tasks, the model provides insights into the neural mechanisms utilized by the auditory cortex to enhance the perception of behaviorally salient sounds.
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Affiliation(s)
- Jordan D Chambers
- NeuroEngineering Laboratory, Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia
| | - Diego Elgueda
- Departamento de Patología Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile.,Institute for Systems Research, University of Maryland, College Park, MD, United States
| | - Jonathan B Fritz
- Institute for Systems Research, University of Maryland, College Park, MD, United States
| | - Shihab A Shamma
- Institute for Systems Research, University of Maryland, College Park, MD, United States.,Laboratoire des Systèmes Perceptifs, École Normale Supérieure, Paris, France
| | - Anthony N Burkitt
- NeuroEngineering Laboratory, Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia
| | - David B Grayden
- NeuroEngineering Laboratory, Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia
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Carbajal GV, Malmierca MS. The Neuronal Basis of Predictive Coding Along the Auditory Pathway: From the Subcortical Roots to Cortical Deviance Detection. Trends Hear 2019; 22:2331216518784822. [PMID: 30022729 PMCID: PMC6053868 DOI: 10.1177/2331216518784822] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In this review, we attempt to integrate the empirical evidence regarding stimulus-specific adaptation (SSA) and mismatch negativity (MMN) under a predictive coding perspective (also known as Bayesian or hierarchical-inference model). We propose a renewed methodology for SSA study, which enables a further decomposition of deviance detection into repetition suppression and prediction error, thanks to the use of two controls previously introduced in MMN research: the many-standards and the cascade sequences. Focusing on data obtained with cellular recordings, we explain how deviance detection and prediction error are generated throughout hierarchical levels of processing, following two vectors of increasing computational complexity and abstraction along the auditory neuraxis: from subcortical toward cortical stations and from lemniscal toward nonlemniscal divisions. Then, we delve into the particular characteristics and contributions of subcortical and cortical structures to this generative mechanism of hierarchical inference, analyzing what is known about the role of neuromodulation and local microcircuitry in the emergence of mismatch signals. Finally, we describe how SSA and MMN are occurring at similar time frame and cortical locations, and both are affected by the manipulation of N-methyl- D-aspartate receptors. We conclude that there is enough empirical evidence to consider SSA and MMN, respectively, as the microscopic and macroscopic manifestations of the same physiological mechanism of deviance detection in the auditory cortex. Hence, the development of a common theoretical framework for SSA and MMN is all the more recommendable for future studies. In this regard, we suggest a shared nomenclature based on the predictive coding interpretation of deviance detection.
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Affiliation(s)
- Guillermo V Carbajal
- 1 Auditory Neuroscience Laboratory (Lab 1), Institute of Neuroscience of Castile and León, University of Salamanca, Salamanca, Spain.,2 Salamanca Institute for Biomedical Research, Spain
| | - Manuel S Malmierca
- 1 Auditory Neuroscience Laboratory (Lab 1), Institute of Neuroscience of Castile and León, University of Salamanca, Salamanca, Spain.,2 Salamanca Institute for Biomedical Research, Spain.,3 Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, Spain
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6
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Becker K, Cana A, Baumgärtner W, Spitzbarth I. p75 Neurotrophin Receptor: A Double-Edged Sword in Pathology and Regeneration of the Central Nervous System. Vet Pathol 2018; 55:786-801. [PMID: 29940812 DOI: 10.1177/0300985818781930] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The low-affinity nerve growth factor receptor p75NTR is a major neurotrophin receptor involved in manifold and pleiotropic functions in the developing and adult central nervous system (CNS). Although known for decades, its entire functions are far from being fully elucidated. Depending on the complex interactions with other receptors and on the cellular context, p75NTR is capable of performing contradictory tasks such as mediating cell death as well as cell survival. In parallel, as a prototype marker for certain differentiation stages of Schwann cells and related CNS aldynoglial cells, p75NTR has recently gained increasing notice as a marker for cells with proposed regenerative potential in CNS diseases, such as demyelinating disease and traumatic CNS injury. Besides its pivotal role as a marker for transplantation candidate cells, recent studies in canine neuroinflammatory CNS conditions also highlight a spontaneous endogenous occurrence of p75NTR-positive glia, which potentially play a role in Schwann cell-mediated CNS remyelination. The aim of the present communication is to review the pleiotropic functions of p75NTR in the CNS with a special emphasis on its role as an immunohistochemical marker in neuropathology. Following a brief illustration of the expression of p75NTR in neurogenesis and in developed neuronal populations, the implications of p75NTR expression in astrocytes, oligodendrocytes, and microglia are addressed. A special focus is put on the role of p75NTR as a cell marker for specific differentiation stages of Schwann cells and a regeneration-promoting CNS population, collectively referred to as aldynoglia.
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Affiliation(s)
- Kathrin Becker
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Armend Cana
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Wolfgang Baumgärtner
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
| | - Ingo Spitzbarth
- 1 Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,2 Center for Systems Neuroscience, Hannover, Germany
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7
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Neural pathways in medial septal cholinergic modulation of chronic pain: distinct contribution of the anterior cingulate cortex and ventral hippocampus. Pain 2018; 159:1550-1561. [DOI: 10.1097/j.pain.0000000000001240] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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8
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Chavez C, Zaborszky L. Basal Forebrain Cholinergic-Auditory Cortical Network: Primary Versus Nonprimary Auditory Cortical Areas. Cereb Cortex 2017; 27:2335-2347. [PMID: 27073229 DOI: 10.1093/cercor/bhw091] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Acetylcholine (ACh) release in the cortex is critical for learning, memory, attention, and plasticity. Here, we explore the cholinergic and noncholinergic projections from the basal forebrain (BF) to the auditory cortex using classical retrograde and monosynaptic viral tracers deposited in electrophysiologically identified regions of the auditory cortex. Cholinergic input to both primary (A1) and nonprimary auditory cortical (belt) areas originates in a restricted area in the caudal BF within the globus pallidus (GP) and in the dorsal part of the substantia innominata (SId). On the other hand, we found significant differences in the proportions of cholinergic and noncholinergic projection neurons to primary and nonprimary auditory areas. Inputs to A1 projecting cholinergic neurons were restricted to the GP, caudate-putamen, and the medial part of the medial geniculate body, including the posterior intralaminar thalamic group. In addition to these areas, afferents to belt-projecting cholinergic neurons originated from broader areas, including the ventral secondary auditory cortex, insular cortex, secondary somatosensory cortex, and the central amygdaloid nucleus. These findings support a specific BF projection pattern to auditory cortical areas. Additionally, these findings point to potential functional differences in how ACh release may be regulated in the A1 and auditory belt areas.
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Affiliation(s)
- Candice Chavez
- Center for Molecular and Behavioral Neuroscience, Rutgers State University, Newark, NJ 07102, USA
| | - Laszlo Zaborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers State University, Newark, NJ 07102, USA
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9
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Mahady LJ, Perez SE, Emerich DF, Wahlberg LU, Mufson EJ. Cholinergic profiles in the Goettingen miniature pig (Sus scrofa domesticus) brain. J Comp Neurol 2016; 525:553-573. [PMID: 27490949 DOI: 10.1002/cne.24087] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 11/10/2022]
Abstract
Central cholinergic structures within the brain of the even-toed hoofed Goettingen miniature domestic pig (Sus scrofa domesticus) were evaluated by immunohistochemical visualization of choline acetyltransferase (ChAT) and the low-affinity neurotrophin receptor, p75NTR . ChAT-immunoreactive (-ir) perikarya were seen in the olfactory tubercle, striatum, medial septal nucleus, vertical and horizontal limbs of the diagonal band of Broca, and the nucleus basalis of Meynert, medial habenular nucleus, zona incerta, neurosecretory arcuate nucleus, cranial motor nuclei III and IV, Edinger-Westphal nucleus, parabigeminal nucleus, pedunculopontine nucleus, and laterodorsal tegmental nucleus. Cholinergic ChAT-ir neurons were also found within transitional cortical areas (insular, cingulate, and piriform cortices) and hippocampus proper. ChAT-ir fibers were seen throughout the dentate gyrus and hippocampus, in the mediodorsal, laterodorsal, anteroventral, and parateanial thalamic nuclei, the fasciculus retroflexus of Meynert, basolateral and basomedial amygdaloid nuclei, anterior pretectal and interpeduncular nuclei, as well as select laminae of the superior colliculus. Double immunofluorescence demonstrated that virtually all ChAT-ir basal forebrain neurons were also p75NTR -positive. The present findings indicate that the central cholinergic system in the miniature pig is similar to other mammalian species. Therefore, the miniature pig may be an appropriate animal model for preclinical studies of neurodegenerative diseases where the cholinergic system is compromised. J. Comp. Neurol. 525:553-573, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Laura J Mahady
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona.,Interdisciplinary Graduate Program in Neuroscience, Arizona State University, Tempe, Arizona
| | - Sylvia E Perez
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
| | | | | | - Elliott J Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, Arizona
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10
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Ayala YA, Malmierca MS. Cholinergic Modulation of Stimulus-Specific Adaptation in the Inferior Colliculus. J Neurosci 2015; 35:12261-72. [PMID: 26338336 PMCID: PMC6605313 DOI: 10.1523/jneurosci.0909-15.2015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 07/13/2015] [Accepted: 07/28/2015] [Indexed: 01/28/2023] Open
Abstract
Neural encoding of an ever-changing acoustic environment is a complex and demanding process that depends on modulation by neuroactive substances. Some neurons of the inferior colliculus (IC) exhibit "stimulus-specific adaptation" (SSA), i.e., a decrease in their response to a repetitive sound, but not to a rare one. Previous studies have demonstrated that acetylcholine (ACh) alters the frequency response areas of auditory neurons and therefore is important in the encoding of spectral information. Here, we address how microiontophoretic application of ACh modulates SSA in the IC of the anesthetized rat. We found that ACh decreased SSA in IC neurons by increasing the response to the repetitive tone. This effect was mainly mediated by muscarinic receptors. The strength of the cholinergic modulation depended on the baseline SSA level, exerting its greatest effect on neurons with intermediate SSA responses across IC subdivisions. Our data demonstrate that the increased availability of ACh exerts transient functional changes in partially adapting IC neurons, enhancing the sensory encoding of the ongoing stimulation. This effect potentially contributes to the propagation of ascending sensory-evoked afferent activity through the thalamus en route to the cortex. SIGNIFICANCE STATEMENT Neural encoding of an ever-changing acoustic environment is a complex and demanding task that may depend on the available levels of neuroactive substances. We explored how the cholinergic inputs affect the responses of neurons in the auditory midbrain that exhibit different degrees of stimulus-specific adaptation (SSA), i.e., a specific decrease in their response to a repeated sound that does not generalize to other, rare sounds. This work addresses the role of cholinergic synaptic inputs as well as the contribution of the muscarinic and nicotinic receptors on SSA. This is the first report on the role of neuromodulation on SSA, and the results contribute to our understanding of the cellular bases for processing low- and high-probability sounds.
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Affiliation(s)
- Yaneri A Ayala
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León and
| | - Manuel S Malmierca
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León and Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, 37007 Salamanca, Spain
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11
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Wu C, Stefanescu RA, Martel DT, Shore SE. Listening to another sense: somatosensory integration in the auditory system. Cell Tissue Res 2015; 361:233-50. [PMID: 25526698 PMCID: PMC4475675 DOI: 10.1007/s00441-014-2074-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/18/2014] [Indexed: 12/19/2022]
Abstract
Conventionally, sensory systems are viewed as separate entities, each with its own physiological process serving a different purpose. However, many functions require integrative inputs from multiple sensory systems and sensory intersection and convergence occur throughout the central nervous system. The neural processes for hearing perception undergo significant modulation by the two other major sensory systems, vision and somatosensation. This synthesis occurs at every level of the ascending auditory pathway: the cochlear nucleus, inferior colliculus, medial geniculate body and the auditory cortex. In this review, we explore the process of multisensory integration from (1) anatomical (inputs and connections), (2) physiological (cellular responses), (3) functional and (4) pathological aspects. We focus on the convergence between auditory and somatosensory inputs in each ascending auditory station. This review highlights the intricacy of sensory processing and offers a multisensory perspective regarding the understanding of sensory disorders.
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Affiliation(s)
- Calvin Wu
- Department of Otolaryngology, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, 48109, USA
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12
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Cortical cholinergic input is required for normal auditory perception and experience-dependent plasticity in adult ferrets. J Neurosci 2013; 33:6659-71. [PMID: 23575862 DOI: 10.1523/jneurosci.5039-12.2013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The nucleus basalis (NB) in the basal forebrain provides most of the cholinergic input to the neocortex and has been implicated in a variety of cognitive functions related to the processing of sensory stimuli. However, the role that cortical acetylcholine release plays in perception remains unclear. Here we show that selective loss of cholinergic NB neurons that project to the cortex reduces the accuracy with which ferrets localize brief sounds and prevents them from adaptively reweighting auditory localization cues in response to chronic occlusion of one ear. Cholinergic input to the cortex was disrupted by making bilateral injections of the immunotoxin ME20.4-SAP into the NB. This produced a substantial loss of both p75 neurotrophin receptor (p75(NTR))-positive and choline acetyltransferase-positive cells in this region and of acetylcholinesterase-positive fibers throughout the auditory cortex. These animals were significantly impaired in their ability to localize short broadband sounds (40-500 ms in duration) in the horizontal plane, with larger cholinergic cell lesions producing greater performance impairments. Although they localized longer sounds with normal accuracy, their response times were significantly longer than controls. Ferrets with cholinergic forebrain lesions were also less able to relearn to localize sound after plugging one ear. In contrast to controls, they exhibited little recovery of localization performance after behavioral training. Together, these results show that cortical cholinergic inputs contribute to the perception of sound source location under normal hearing conditions and play a critical role in allowing the auditory system to adapt to changes in the spatial cues available.
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