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Offutt SJ, Rose JE, Crawford KJ, Harris ML, Lim HH. Gradients of response latencies and temporal precision of auditory neurons extend across the whole inferior colliculus. J Neurophysiol 2023; 130:719-735. [PMID: 37609690 PMCID: PMC10650646 DOI: 10.1152/jn.00461.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023] Open
Abstract
Neural responses to acoustic stimulation have long been studied throughout the auditory system to understand how sound information is coded for perception. Within the inferior colliculus (IC), a majority of the studies have focused predominantly on characterizing neural responses within the central region (ICC), as it is viewed as part of the lemniscal system mainly responsible for auditory perception. In contrast, the responses of outer cortices (ICO) have largely been unexplored, though they also function in auditory perception tasks. Therefore, we sought to expand on previous work by completing a three-dimensional (3-D) functional mapping study of the whole IC. We analyzed responses to different pure tone and broadband noise stimuli across all IC subregions and correlated those responses with over 2,000 recording locations across the IC. Our study revealed there are well-organized trends for temporal response parameters across the full IC that do not show a clear distinction at the ICC and ICO border. These gradients span from slow, imprecise responses in the caudal-medial IC to fast, precise responses in the rostral-lateral IC, regardless of subregion, including the fastest responses located in the ICO. These trends were consistent at various acoustic stimulation levels. Weaker spatial trends could be found for response duration and spontaneous activity. Apart from tonotopic organization, spatial trends were not apparent for spectral response properties. Overall, these detailed acoustic response maps across the whole IC provide new insights into the organization and function of the IC.NEW & NOTEWORTHY Study of the inferior colliculus (IC) has largely focused on the central nucleus, with little exploration of the outer cortices. Here, we systematically assessed the acoustic response properties from over 2,000 locations in different subregions of the IC. The results revealed spatial trends in temporal response patterns that span all subregions. Furthermore, two populations of temporal response types emerged for neurons in the outer cortices that may contribute to their functional roles in auditory tasks.
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Affiliation(s)
- Sarah J Offutt
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Jessica E Rose
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kellie J Crawford
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Megan L Harris
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, Minnesota, United States
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States
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2
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Gloeckner CD, Nocon JC, Lim HH. Topographic and widespread auditory modulation of the somatosensory cortex: potential for bimodal sound and body stimulation for pain treatment. J Neural Eng 2022; 19. [PMID: 35671702 DOI: 10.1088/1741-2552/ac7665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/07/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE There has been growing interest in understanding multisensory integration in the cortex through activation of multiple sensory and motor pathways to treat brain disorders, such as tinnitus or essential tremors. For tinnitus, previous studies show that combined sound and body stimulation can modulate the auditory pathway and lead to significant improvements in tinnitus symptoms. Considering that tinnitus is a type of chronic auditory pain, bimodal stimulation could potentially alter activity in the somatosensory pathway relevant for treating chronic pain. As an initial step towards that goal, we mapped and characterized neuromodulation effects in the somatosensory cortex (SC) in response to sound and/or electrical stimulation of the body. APPROACH We first mapped the topographic organization of activity across the SC of ketamine-anesthetized guinea pigs through electrical stimulation of different body locations using subcutaneous needle electrodes or with broadband acoustic stimulation. We then characterized how neural activity in different parts of the SC could be facilitated or suppressed with bimodal stimulation. MAIN RESULTS The topography in the SC of guinea pigs in response to electrical stimulation of the body aligns consistently to that shown in previous rodent studies. Interestingly, auditory broadband noise stimulation primarily excited SC areas that typically respond to stimulation of lower body locations. Although there was only a small subset of SC locations that were excited by acoustic stimulation alone, all SC recording sites could be altered (facilitated or suppressed) with bimodal stimulation. Furthermore, specific regions of the SC could be modulated by stimulating an appropriate body region combined with broadband noise. SIGNIFICANCE These findings show that bimodal stimulation can excite or modulate firing across a widespread yet targeted population of SC neurons. This approach may provide a non-invasive method for altering or disrupting abnormal firing patterns within certain parts of the SC for chronic pain treatment.
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Affiliation(s)
- Cory D Gloeckner
- University of Minnesota Duluth, 1305 Ordean Court, Duluth, Minnesota, 55812, UNITED STATES
| | - Jian C Nocon
- Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts, 02215, UNITED STATES
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street SE, Minneapolis, MN 55455, USA, Minneapolis, Minnesota, 55455, UNITED STATES
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3
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Sitek KR, Calabrese E, Johnson GA, Ghosh SS, Chandrasekaran B. Structural Connectivity of Human Inferior Colliculus Subdivisions Using in vivo and post mortem Diffusion MRI Tractography. Front Neurosci 2022; 16:751595. [PMID: 35392412 PMCID: PMC8981148 DOI: 10.3389/fnins.2022.751595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 01/27/2022] [Indexed: 12/05/2022] Open
Abstract
Inferior colliculus (IC) is an obligatory station along the ascending auditory pathway that also has a high degree of top-down convergence via efferent pathways, making it a major computational hub. Animal models have attributed critical roles for the IC in in mediating auditory plasticity, egocentric selection, and noise exclusion. IC contains multiple functionally distinct subdivisions. These include a central nucleus that predominantly receives ascending inputs and external and dorsal nuclei that receive more heterogeneous inputs, including descending and multisensory connections. Subdivisions of human IC have been challenging to identify and quantify using standard brain imaging techniques such as MRI, and the connectivity of each of these subnuclei has not been identified in the human brain. In this study, we estimated the connectivity of human IC subdivisions with diffusion MRI (dMRI) tractography, using both anatomical-based seed analysis as well as unsupervised k-means clustering. We demonstrate sensitivity of tractography to overall IC connections in both high resolution post mortem and in vivo datasets. k-Means clustering of the IC streamlines in both the post mortem and in vivo datasets generally segregated streamlines based on their terminus beyond IC, such as brainstem, thalamus, or contralateral IC. Using fine-grained anatomical segmentations of the major IC subdivisions, the post mortem dataset exhibited unique connectivity patterns from each subdivision, including commissural connections through dorsal IC and lateral lemniscal connections to central and external IC. The subdivisions were less distinct in the context of in vivo connectivity, although lateral lemniscal connections were again highest to central and external IC. Overall, the unsupervised and anatomically driven methods provide converging evidence for distinct connectivity profiles for each of the IC subdivisions in both post mortem and in vivo datasets, suggesting that dMRI tractography with high quality data is sensitive to neural pathways involved in auditory processing as well as top-down control of incoming auditory information.
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Affiliation(s)
- Kevin R. Sitek
- SoundBrain Lab, Brain and Auditory Sciences Research Initiative, Department of Communication and Science Disorders, University of Pittsburgh, Pittsburgh, PA, United States
- *Correspondence: Kevin R. Sitek,
| | - Evan Calabrese
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - G. Allan Johnson
- Center for In Vivo Microscopy, Duke University, Durham, NC, United States
| | - Satrajit S. Ghosh
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States
- Department of Otolaryngology – Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Bharath Chandrasekaran
- SoundBrain Lab, Brain and Auditory Sciences Research Initiative, Department of Communication and Science Disorders, University of Pittsburgh, Pittsburgh, PA, United States
- Bharath Chandrasekaran,
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Wang X, Zhang Y, Bai S, Qi R, Sun H, Li R, Zhu L, Cao X, Jia G, Li X, Gao L. Corticofugal Modulation of Temporal and Rate Representations in the Inferior Colliculus of the Awake Marmoset. Cereb Cortex 2022; 32:4080-4097. [PMID: 35029654 DOI: 10.1093/cercor/bhab467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/12/2021] [Accepted: 11/16/2021] [Indexed: 11/14/2022] Open
Abstract
Temporal processing is crucial for auditory perception and cognition, especially for communication sounds. Previous studies have shown that the auditory cortex and the thalamus use temporal and rate representations to encode slowly and rapidly changing time-varying sounds. However, how the primate inferior colliculus (IC) encodes time-varying sounds at the millisecond scale remains unclear. In this study, we investigated the temporal processing by IC neurons in awake marmosets to Gaussian click trains with varying interclick intervals (2-100 ms). Strikingly, we found that 28% of IC neurons exhibited rate representation with nonsynchronized responses, which is in sharp contrast to the current view that the IC only uses a temporal representation to encode time-varying signals. Moreover, IC neurons with rate representation exhibited response properties distinct from those with temporal representation. We further demonstrated that reversible inactivation of the primary auditory cortex modulated 17% of the stimulus-synchronized responses and 21% of the nonsynchronized responses of IC neurons, revealing that cortico-colliculus projections play a role, but not a crucial one, in temporal processing in the IC. This study has significantly advanced our understanding of temporal processing in the IC of awake animals and provides new insights into temporal processing from the midbrain to the cortex.
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Affiliation(s)
- Xiaohui Wang
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Yuanqing Zhang
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Siyi Bai
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Runze Qi
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Hao Sun
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Rui Li
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Lin Zhu
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Xinyuan Cao
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Guoqiang Jia
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Xinjian Li
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
| | - Lixia Gao
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering and Instrument Science, School of Medicine, Zhejiang University, Hangzhou 310000, China
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Asilador A, Llano DA. Top-Down Inference in the Auditory System: Potential Roles for Corticofugal Projections. Front Neural Circuits 2021; 14:615259. [PMID: 33551756 PMCID: PMC7862336 DOI: 10.3389/fncir.2020.615259] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/17/2020] [Indexed: 01/28/2023] Open
Abstract
It has become widely accepted that humans use contextual information to infer the meaning of ambiguous acoustic signals. In speech, for example, high-level semantic, syntactic, or lexical information shape our understanding of a phoneme buried in noise. Most current theories to explain this phenomenon rely on hierarchical predictive coding models involving a set of Bayesian priors emanating from high-level brain regions (e.g., prefrontal cortex) that are used to influence processing at lower-levels of the cortical sensory hierarchy (e.g., auditory cortex). As such, virtually all proposed models to explain top-down facilitation are focused on intracortical connections, and consequently, subcortical nuclei have scarcely been discussed in this context. However, subcortical auditory nuclei receive massive, heterogeneous, and cascading descending projections at every level of the sensory hierarchy, and activation of these systems has been shown to improve speech recognition. It is not yet clear whether or how top-down modulation to resolve ambiguous sounds calls upon these corticofugal projections. Here, we review the literature on top-down modulation in the auditory system, primarily focused on humans and cortical imaging/recording methods, and attempt to relate these findings to a growing animal literature, which has primarily been focused on corticofugal projections. We argue that corticofugal pathways contain the requisite circuitry to implement predictive coding mechanisms to facilitate perception of complex sounds and that top-down modulation at early (i.e., subcortical) stages of processing complement modulation at later (i.e., cortical) stages of processing. Finally, we suggest experimental approaches for future studies on this topic.
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Affiliation(s)
- Alexander Asilador
- Neuroscience Program, The University of Illinois at Urbana-Champaign, Champaign, IL, United States
- Beckman Institute for Advanced Science and Technology, Urbana, IL, United States
| | - Daniel A. Llano
- Neuroscience Program, The University of Illinois at Urbana-Champaign, Champaign, IL, United States
- Beckman Institute for Advanced Science and Technology, Urbana, IL, United States
- Molecular and Integrative Physiology, The University of Illinois at Urbana-Champaign, Champaign, IL, United States
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6
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Qi J, Zhang Z, He N, Liu X, Zhang C, Yan J. Cortical Stimulation Induces Excitatory Postsynaptic Potentials of Inferior Colliculus Neurons in a Frequency-Specific Manner. Front Neural Circuits 2020; 14:591986. [PMID: 33192337 PMCID: PMC7649762 DOI: 10.3389/fncir.2020.591986] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/24/2020] [Indexed: 11/30/2022] Open
Abstract
Corticofugal modulation of auditory responses in subcortical nuclei has been extensively studied whereas corticofugal synaptic transmission must still be characterized. This study examined postsynaptic potentials of the corticocollicular system, i.e., the projections from the primary auditory cortex (AI) to the central nucleus of the inferior colliculus (ICc) of the midbrain, in anesthetized C57 mice. We used focal electrical stimulation at the microampere level to activate the AI (ESAI) and in vivo whole-cell current-clamp to record the membrane potentials of ICc neurons. Following the whole-cell patch-clamp recording of 88 ICc neurons, 42 ICc neurons showed ESAI-evoked changes in the membrane potentials. We found that the ESAI induced inhibitory postsynaptic potentials in 6 out of 42 ICc neurons but only when the stimulus current was 96 μA or higher. In the remaining 36 ICc neurons, excitatory postsynaptic potentials (EPSPs) were induced at a much lower stimulus current. The 36 ICc neurons exhibiting EPSPs were categorized into physiologically matched neurons (n = 12) when the characteristic frequencies of the stimulated AI and recorded ICc neurons were similar (≤1 kHz) and unmatched neurons (n = 24) when they were different (>1 kHz). Compared to unmatched neurons, matched neurons exhibited a significantly lower threshold of evoking noticeable EPSP, greater EPSP amplitude, and shorter EPSP latency. Our data allow us to propose that corticocollicular synaptic transmission is primarily excitatory and that synaptic efficacy is dependent on the relationship of the frequency tunings between AI and ICc neurons.
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Affiliation(s)
- Jiyao Qi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Zizhen Zhang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Na He
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Xiuping Liu
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Caseng Zhang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jun Yan
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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7
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Blackwell JM, Lesicko AMH, Rao W, De Biasi M, Geffen MN. Auditory cortex shapes sound responses in the inferior colliculus. eLife 2020; 9:e51890. [PMID: 32003747 PMCID: PMC7062464 DOI: 10.7554/elife.51890] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/31/2020] [Indexed: 12/30/2022] Open
Abstract
The extensive feedback from the auditory cortex (AC) to the inferior colliculus (IC) supports critical aspects of auditory behavior but has not been extensively characterized. Previous studies demonstrated that activity in IC is altered by focal electrical stimulation and pharmacological inactivation of AC, but these methods lack the ability to selectively manipulate projection neurons. We measured the effects of selective optogenetic modulation of cortico-collicular feedback projections on IC sound responses in mice. Activation of feedback increased spontaneous activity and decreased stimulus selectivity in IC, whereas suppression had no effect. To further understand how microcircuits in AC may control collicular activity, we optogenetically modulated the activity of different cortical neuronal subtypes, specifically parvalbumin-positive (PV) and somatostatin-positive (SST) inhibitory interneurons. We found that modulating the activity of either type of interneuron did not affect IC sound-evoked activity. Combined, our results identify that activation of excitatory projections, but not inhibition-driven changes in cortical activity, affects collicular sound responses.
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Affiliation(s)
- Jennifer M Blackwell
- Department of OtorhinolaryngologyUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of Neurobiology and BehaviorStony Brook UniversityStony BrookUnited States
| | - Alexandria MH Lesicko
- Department of OtorhinolaryngologyUniversity of PennsylvaniaPhiladelphiaUnited States
| | - Winnie Rao
- Department of OtorhinolaryngologyUniversity of PennsylvaniaPhiladelphiaUnited States
| | - Mariella De Biasi
- Department of PsychiatryUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of Systems Pharmacology and Experimental TherapeuticsUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of NeuroscienceUniversity of PennsylvaniaPhiladelphiaUnited States
| | - Maria N Geffen
- Department of OtorhinolaryngologyUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of NeuroscienceUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of NeurologyUniversity of PennsylvaniaPhiladelphiaUnited States
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8
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García-García R, Guerrero JF, Lavilla-Miyasato M, Magdalena JR, Ordoño JF, Llansola M, Montoliu C, Teruel-Martí V, Felipo V. Hyperammonemia alters the mismatch negativity in the auditory evoked potential by altering functional connectivity and neurotransmission. J Neurochem 2020; 154:56-70. [PMID: 31840253 DOI: 10.1111/jnc.14941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/18/2019] [Accepted: 12/11/2019] [Indexed: 12/27/2022]
Abstract
Minimal hepatic encephalopathy (MHE) is a neuropsychiatric syndrome produced by central nervous system dysfunction subsequent to liver disease. Hyperammonemia and inflammation act synergistically to alter neurotransmission, leading to the cognitive and motor alterations in MHE, which are reproduced in rat models of chronic hyperammonemia. Patients with MHE show altered functional connectivity in different neural networks and a reduced response in the cognitive potential mismatch negativity (MMN), which correlates with attention deficits. The mechanisms by which MMN is altered in MHE remain unknown. The objectives of this work are as follows: To assess if rats with chronic hyperammonemia reproduce the reduced response in the MMN found in patients with MHE. Analyze the functional connectivity between the areas (CA1 area of the dorsal hippocampus, prelimbic cortex, primary auditory cortex, and central inferior colliculus) involved in the generation of the MMN and its possible alterations in hyperammonemia. Granger causality analysis has been applied to detect the net flow of information between the population neuronal activities recorded from a local field potential approach. Analyze if altered MMN response in hyperammonemia is associated with alterations in glutamatergic and GABAergic neurotransmission. Extracellular levels of the neurotransmitters and/or membrane expression of their receptors have been analyzed after the tissue isolation of the four target sites. The results show that rats with chronic hyperammonemia show reduced MMN response in hippocampus, mimicking the reduced MMN response of patients with MHE. This is associated with altered functional connectivity between the areas involved in the generation of the MMN. Hyperammonemia also alters membrane expression of glutamate and GABA receptors in hippocampus and reduces the changes in extracellular GABA and glutamate induced by the MMN paradigm of auditory stimulus in hippocampus of control rats. The changes in glutamatergic and GABAergic neurotransmission and in functional connectivity between the brain areas analyzed would contribute to the impairment of the MMN response in rats with hyperammonemia and, likely, also in patients with MHE.
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Affiliation(s)
- Raquel García-García
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain
| | - Juan F Guerrero
- Group of Digital Signal Processing, Department of Electronic Engineer. School of Superior Engineer, University of Valencia, Valencia, Spain
| | | | - Jose R Magdalena
- Group of Digital Signal Processing, Department of Electronic Engineer. School of Superior Engineer, University of Valencia, Valencia, Spain
| | - Juan F Ordoño
- Neurophysiology Service, Hospital Arnau de Vilanova, Valencia, Spain
| | - Marta Llansola
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain
| | - Carmina Montoliu
- Research Foundation Hospital Clínico Valencia. INCLIVA Valencia, Valencia, Spain.,Department of Pathology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Vicent Teruel-Martí
- Laboratory of Neuronal Circuits, Department of Anatomy and Human Embriology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Principe Felipe, Valencia, Spain
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Expression and Localization of Kv1.1 and Kv3.1b Potassium Channels in the Cochlear Nucleus and Inferior Colliculus after Long-Term Auditory Deafferentation. Brain Sci 2020; 10:brainsci10010035. [PMID: 31936259 PMCID: PMC7017294 DOI: 10.3390/brainsci10010035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 12/14/2022] Open
Abstract
Deafness affects the expression and distribution of voltage-dependent potassium channels (Kvs) of central auditory neurons in the short-term, i.e., hours to days, but the consequences in the expression of Kvs after long-term deafness remain unknown. We tested expression and distribution of Kv1.1 and Kv3.1b, key for auditory processing, in the rat cochlear nucleus (CN), and in the inferior colliculus (IC), at 1, 15 and 90 days after mechanical lesion of the cochlea, using a combination of qRT-PCR and Western blot in the whole CN, along with semi-quantitative immunocytochemistry in the AVCN, where the role of both Kvs in the control of excitability for accurate auditory timing signal processing is well established. Neither Kv1.1/Kv3.1b mRNA or protein expression changed significantly in the CN between 1 and 15 days after deafness. At 90 days post-lesion, however, mRNA and protein expression for both Kvs increased, suggesting that regulation of Kv1.1 and Kv3.1b expression is part of cellular mechanisms for long-term adaptation to auditory deprivation in the CN. Consistent with these findings, immunocytochemistry showed increased labeling intensity for both Kvs in the AVCN at day 90 after cochlear lesion. This increase argues that up-regulation of Kv1.1 and Kv3.1b in AVCN neurons may be required to adapt intrinsic excitability to altered input over the long term after auditory deprivation. Contrary to these findings in the CN, expression levels of Kv1.1 and Kv3.1b in the IC did not undergo major changes after cochlear lesion. In particular, there was no evidence of long-term up-regulation of either Kv1.1 or Kv3.1b, supporting that such post-lesion adaptive mechanism may not be needed in the IC. These results reveal that post-lesion adaptations do not necessarily involve stereotyped plastic mechanisms along the entire auditory pathway.
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Guo H, Hamilton M, Offutt SJ, Gloeckner CD, Li T, Kim Y, Legon W, Alford JK, Lim HH. Ultrasound Produces Extensive Brain Activation via a Cochlear Pathway. Neuron 2018; 98:1020-1030.e4. [PMID: 29804919 DOI: 10.1016/j.neuron.2018.04.036] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/21/2018] [Accepted: 04/27/2018] [Indexed: 12/25/2022]
Abstract
Ultrasound (US) can noninvasively activate intact brain circuits, making it a promising neuromodulation technique. However, little is known about the underlying mechanism. Here, we apply transcranial US and perform brain mapping studies in guinea pigs using extracellular electrophysiology. We find that US elicits extensive activation across cortical and subcortical brain regions. However, transection of the auditory nerves or removal of cochlear fluids eliminates the US-induced activity, revealing an indirect auditory mechanism for US neural activation. Our findings indicate that US activates the ascending auditory system through a cochlear pathway, which can activate other non-auditory regions through cross-modal projections. This cochlear pathway mechanism challenges the idea that US can directly activate neurons in the intact brain, suggesting that future US stimulation studies will need to control for this effect to reach reliable conclusions.
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Affiliation(s)
- Hongsun Guo
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Mark Hamilton
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sarah J Offutt
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Cory D Gloeckner
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tianqi Li
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yohan Kim
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Wynn Legon
- Department of Rehabilitation Medicine, Medical School, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neurological Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jamu K Alford
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, MN 55455, USA
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11
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Role of Autophagy in Auditory System Development and Survival. JOURNAL OF OTORHINOLARYNGOLOGY, HEARING AND BALANCE MEDICINE 2018. [DOI: 10.3390/ohbm1010007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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12
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Abstract
Most behaviors in mammals are directly or indirectly guided by prior experience and therefore depend on the ability of our brains to form memories. The ability to form an association between an initially possibly neutral sensory stimulus and its behavioral relevance is essential for our ability to navigate in a changing environment. The formation of a memory is a complex process involving many areas of the brain. In this chapter we review classic and recent work that has shed light on the specific contribution of sensory cortical areas to the formation of associative memories. We discuss synaptic and circuit mechanisms that mediate plastic adaptations of functional properties in individual neurons as well as larger neuronal populations forming topographically organized representations. Furthermore, we describe commonly used behavioral paradigms that are used to study the mechanisms of memory formation. We focus on the auditory modality that is receiving increasing attention for the study of associative memory in rodent model systems. We argue that sensory cortical areas may play an important role for the memory-dependent categorical recognition of previously encountered sensory stimuli.
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Affiliation(s)
- Dominik Aschauer
- Institute of Physiology, Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Simon Rumpel
- Institute of Physiology, Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg University, Mainz, Germany.
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13
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Mulders WHAM, Vooys V, Makowiecki K, Tang AD, Rodger J. The effects of repetitive transcranial magnetic stimulation in an animal model of tinnitus. Sci Rep 2016; 6:38234. [PMID: 27905540 PMCID: PMC5131273 DOI: 10.1038/srep38234] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/07/2016] [Indexed: 02/04/2023] Open
Abstract
Tinnitus (phantom auditory perception associated with hearing loss) can seriously affect wellbeing. Its neural substrate is unknown however it has been linked with abnormal activity in auditory pathways. Though no cure currently exists, repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce tinnitus in some patients, possibly via induction of cortical plasticity involving brain derived neurotrophic factor (BDNF). We examined whether low intensity rTMS (LI-rTMS) alleviates signs of tinnitus in a guinea pig model and whether this involves changes in BDNF expression and hyperactivity in inferior colliculus. Acoustic trauma was used to evoke hearing loss, central hyperactivity and tinnitus. When animals developed tinnitus, treatment commenced (10 sessions of 10 minutes 1 Hz LI-rTMS or sham over auditory cortex over 14 days). After treatment ceased animals were tested for tinnitus, underwent single-neuron recordings in inferior colliculus to assess hyperactivity and samples from cortex and inferior colliculus were taken for BDNF ELISA. Analysis revealed a significant reduction of tinnitus after LI-rTMS compared to sham, without a statistical significant effect on BDNF levels or hyperactivity. This suggests that LI-rTMS alleviates behavioural signs of tinnitus by a mechanism independent of inferior colliculus hyperactivity and BDNF levels and opens novel therapeutic avenues for tinnitus treatment.
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Affiliation(s)
- Wilhelmina H A M Mulders
- The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Vanessa Vooys
- The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Kalina Makowiecki
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Alex D Tang
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Jennifer Rodger
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
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14
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Ibrahim LA, Mesik L, Ji XY, Fang Q, Li HF, Li YT, Zingg B, Zhang LI, Tao HW. Cross-Modality Sharpening of Visual Cortical Processing through Layer-1-Mediated Inhibition and Disinhibition. Neuron 2016; 89:1031-45. [PMID: 26898778 DOI: 10.1016/j.neuron.2016.01.027] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/08/2015] [Accepted: 01/12/2016] [Indexed: 11/18/2022]
Abstract
Cross-modality interaction in sensory perception is advantageous for animals' survival. How cortical sensory processing is cross-modally modulated and what are the underlying neural circuits remain poorly understood. In mouse primary visual cortex (V1), we discovered that orientation selectivity of layer (L)2/3, but not L4, excitatory neurons was sharpened in the presence of sound or optogenetic activation of projections from primary auditory cortex (A1) to V1. The effect was manifested by decreased average visual responses yet increased responses at the preferred orientation. It was more pronounced at lower visual contrast and was diminished by suppressing L1 activity. L1 neurons were strongly innervated by A1-V1 axons and excited by sound, while visual responses of L2/L3 vasoactive intestinal peptide (VIP) neurons were suppressed by sound, both preferentially at the cell's preferred orientation. These results suggest that the cross-modality modulation is achieved primarily through L1 neuron- and L2/L3 VIP-cell-mediated inhibitory and disinhibitory circuits.
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Affiliation(s)
- Leena A Ibrahim
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90033, USA
| | - Lukas Mesik
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90033, USA
| | - Xu-Ying Ji
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Qi Fang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90033, USA
| | - Hai-Fu Li
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Ya-Tang Li
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Brian Zingg
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90033, USA
| | - Li I Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
| | - Huizhong Whit Tao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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15
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Descending and tonotopic projection patterns from the auditory cortex to the inferior colliculus. Neuroscience 2015; 300:325-37. [DOI: 10.1016/j.neuroscience.2015.05.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 04/27/2015] [Accepted: 05/14/2015] [Indexed: 11/20/2022]
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16
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Auditory cortex directs the input-specific remodeling of thalamus. Hear Res 2015; 328:1-7. [PMID: 26143340 DOI: 10.1016/j.heares.2015.06.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/10/2015] [Accepted: 06/23/2015] [Indexed: 01/09/2023]
Abstract
Input-specific remodeling is observed both in the primary auditory cortex (AI) and the ventral division of the medial geniculate body of the thalamus (MGBv) through motivation such as learning. Here, we show the role of AI in the MGBv remodeling induced by the electrical stimulation (ES) of the central division of the inferior colliculus (ICc). For the MGBv neurons with frequency tunings different from those of electrically stimulated ICc neurons, their frequency tunings shifted towards the tunings of the ICc neurons. AI neurons also showed this input-specific remodeling after ES of the ICc (ESICc). Interestingly, the input-specific remodeling of MGBv was eliminated when the AI was inactivated using cortical application of muscimol. For the MGBv neurons tuned to the same frequency as the stimulated ICc neurons, their tunings were kept but their responses were facilitated after the ESICc. In contrast to the input-specific tuning shifts, this facilitation was rarely impacted by the AI inactivation. Thus, we conclude that AI directs the input-specific remodeling of MGBv induced by ESICc. It is suggested that the tuning shift in the MGBv primarily takes place in the AI and is relayed to the MGBv through the corticofugal system while the MGBv mainly highlights the frequency information emphasized in ICc.
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17
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Markovitz CD, Hogan PS, Wesen KA, Lim HH. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity. J Neural Eng 2015; 12:026006. [PMID: 25686163 PMCID: PMC4359690 DOI: 10.1088/1741-2560/12/2/026006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. APPROACH We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. MAIN RESULTS All eight stimulated AC subregions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. SIGNIFICANCE We propose that the corticofugal system is designed to decrease the brain's input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders.
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Affiliation(s)
- Craig D. Markovitz
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Patrick S. Hogan
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Kyle A. Wesen
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Hubert H. Lim
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
- University of Minnesota, Department of Otolaryngology-Head and Neck Surgery, Minneapolis, MN USA
- University of Minnesota, Institute for Translational Neuroscience, Minneapolis, MN USA
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18
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Markovitz CD, Smith BT, Gloeckner CD, Lim HH. Investigating a new neuromodulation treatment for brain disorders using synchronized activation of multimodal pathways. Sci Rep 2015; 5:9462. [PMID: 25804410 PMCID: PMC4372796 DOI: 10.1038/srep09462] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/06/2015] [Indexed: 11/21/2022] Open
Abstract
Neuromodulation is an increasingly accepted treatment for neurological and psychiatric disorders but is limited by its invasiveness or its inability to target deep brain structures using noninvasive techniques. We propose a new concept called Multimodal Synchronization Therapy (mSync) for achieving targeted activation of the brain via noninvasive and precisely timed activation of auditory, visual, somatosensory, motor, cognitive, and limbic pathways. In this initial study in guinea pigs, we investigated mSync using combined activation of just the auditory and somatosensory pathways, which induced differential and timing dependent plasticity in neural firing within deep brain and cortical regions of the auditory system. Furthermore, by varying the location of somatosensory stimulation across the body, we increased or decreased spiking activity across different neurons. These encouraging results demonstrate the feasibility of systematically modulating the brain using mSync. Considering that hearing disorders such as tinnitus and hyperacusis have been linked to abnormal and hyperactive firing patterns within the auditory system, these results open up the possibility for using mSync to decrease this pathological activity by varying stimulation parameters. Incorporating multiple types of pathways beyond just auditory and somatosensory inputs and using other activation patterns may enable treatment of various brain disorders.
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Affiliation(s)
- Craig D Markovitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Benjamin T Smith
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Cory D Gloeckner
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Hubert H Lim
- 1] Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA [2] Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Minneapolis, MN USA [3] Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN USA
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19
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Malmierca MS, Anderson LA, Antunes FM. The cortical modulation of stimulus-specific adaptation in the auditory midbrain and thalamus: a potential neuronal correlate for predictive coding. Front Syst Neurosci 2015; 9:19. [PMID: 25805974 PMCID: PMC4353371 DOI: 10.3389/fnsys.2015.00019] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/03/2015] [Indexed: 02/02/2023] Open
Abstract
To follow an ever-changing auditory scene, the auditory brain is continuously creating a representation of the past to form expectations about the future. Unexpected events will produce an error in the predictions that should “trigger” the network’s response. Indeed, neurons in the auditory midbrain, thalamus and cortex, respond to rarely occurring sounds while adapting to frequently repeated ones, i.e., they exhibit stimulus specific adaptation (SSA). SSA cannot be explained solely by intrinsic membrane properties, but likely involves the participation of the network. Thus, SSA is envisaged as a high order form of adaptation that requires the influence of cortical areas. However, present research supports the hypothesis that SSA, at least in its simplest form (i.e., to frequency deviants), can be transmitted in a bottom-up manner through the auditory pathway. Here, we briefly review the underlying neuroanatomy of the corticofugal projections before discussing state of the art studies which demonstrate that SSA present in the medial geniculate body (MGB) and inferior colliculus (IC) is not inherited from the cortex but can be modulated by the cortex via the corticofugal pathways. By modulating the gain of neurons in the thalamus and midbrain, the auditory cortex (AC) would refine SSA subcortically, preventing irrelevant information from reaching the cortex.
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Affiliation(s)
- Manuel S Malmierca
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCyL), University of Salamanca Salamanca, Spain ; Faculty of Medicine, Department of Cell Biology and Pathology, University of Salamanca Salamanca, Spain
| | - Lucy A Anderson
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCyL), University of Salamanca Salamanca, Spain
| | - Flora M Antunes
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCyL), University of Salamanca Salamanca, Spain
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20
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Offutt SJ, Ryan KJ, Konop AE, Lim HH. Suppression and facilitation of auditory neurons through coordinated acoustic and midbrain stimulation: investigating a deep brain stimulator for tinnitus. J Neural Eng 2014; 11:066001. [PMID: 25307351 PMCID: PMC4244264 DOI: 10.1088/1741-2560/11/6/066001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE The inferior colliculus (IC) is the primary processing center of auditory information in the midbrain and is one site of tinnitus-related activity. One potential option for suppressing the tinnitus percept is through deep brain stimulation via the auditory midbrain implant (AMI), which is designed for hearing restoration and is already being implanted in deaf patients who also have tinnitus. However, to assess the feasibility of AMI stimulation for tinnitus treatment we first need to characterize the functional connectivity within the IC. Previous studies have suggested modulatory projections from the dorsal cortex of the IC (ICD) to the central nucleus of the IC (ICC), though the functional properties of these projections need to be determined. APPROACH In this study, we investigated the effects of electrical stimulation of the ICD on acoustic-driven activity within the ICC in ketamine-anesthetized guinea pigs. MAIN RESULTS We observed ICD stimulation induces both suppressive and facilitatory changes across ICC that can occur immediately during stimulation and remain after stimulation. Additionally, ICD stimulation paired with broadband noise stimulation at a specific delay can induce greater suppressive than facilitatory effects, especially when stimulating in more rostral and medial ICD locations. SIGNIFICANCE These findings demonstrate that ICD stimulation can induce specific types of plastic changes in ICC activity, which may be relevant for treating tinnitus. By using the AMI with electrode sites positioned with the ICD and the ICC, the modulatory effects of ICD stimulation can be tested directly in tinnitus patients.
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Affiliation(s)
- Sarah J. Offutt
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Kellie J. Ryan
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Alexander E. Konop
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
| | - Hubert H. Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, USA
- Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, USA
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21
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Straka MM, McMahon M, Markovitz CD, Lim HH. Effects of location and timing of co-activated neurons in the auditory midbrain on cortical activity: implications for a new central auditory prosthesis. J Neural Eng 2014; 11:046021. [PMID: 25003629 DOI: 10.1088/1741-2560/11/4/046021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE An increasing number of deaf individuals are being implanted with central auditory prostheses, but their performance has generally been poorer than for cochlear implant users. The goal of this study is to investigate stimulation strategies for improving hearing performance with a new auditory midbrain implant (AMI). Previous studies have shown that repeated electrical stimulation of a single site in each isofrequency lamina of the central nucleus of the inferior colliculus (ICC) causes strong suppressive effects in elicited responses within the primary auditory cortex (A1). Here we investigate if improved cortical activity can be achieved by co-activating neurons with different timing and locations across an ICC lamina and if this cortical activity varies across A1. APPROACH We electrically stimulated two sites at different locations across an isofrequency ICC lamina using varying delays in ketamine-anesthetized guinea pigs. We recorded and analyzed spike activity and local field potentials across different layers and locations of A1. RESULTS Co-activating two sites within an isofrequency lamina with short inter-pulse intervals (<5 ms) could elicit cortical activity that is enhanced beyond a linear summation of activity elicited by the individual sites. A significantly greater extent of normalized cortical activity was observed for stimulation of the rostral-lateral region of an ICC lamina compared to the caudal-medial region. We did not identify any location trends across A1, but the most cortical enhancement was observed in supragranular layers, suggesting further integration of the stimuli through the cortical layers. SIGNIFICANCE The topographic organization identified by this study provides further evidence for the presence of functional zones across an ICC lamina with locations consistent with those identified by previous studies. Clinically, these results suggest that co-activating different neural populations in the rostral-lateral ICC rather than the caudal-medial ICC using the AMI may improve or elicit different types of hearing capabilities.
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Affiliation(s)
- Małgorzata M Straka
- Department of Biomedical Engineering, University of Minnesota, Twin Cities 312 Church St SE, Minneapolis, MN 55455, USA
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22
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Kong L, Xiong C, Li L, Yan J. Frequency-specific corticofugal modulation of the dorsal cochlear nucleus in mice. Front Syst Neurosci 2014; 8:125. [PMID: 25071477 PMCID: PMC4076887 DOI: 10.3389/fnsys.2014.00125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 06/16/2014] [Indexed: 01/03/2023] Open
Abstract
The primary auditory cortex (AI) modulates the sound information processing in the lemniscal subcortical nuclei, including the anteroventral cochlear nucleus (AVCN), in a frequency-specific manner. The dorsal cochlear nucleus (DCN) is a non-lemniscal subcortical nucleus but it is tonotopically organized like the AVCN. However, it remains unclear how the AI modulates the sound information processing in the DCN. This study examined the impact of focal electrical stimulation of AI on the auditory responses of the DCN neurons in mice. We found that the electrical stimulation induced significant changes in the best frequency (BF) of DCN neurons. The changes in the BFs were highly specific to the BF differences between the stimulated AI neurons and the recorded DCN neurons. The DCN BFs shifted higher when the AI BFs were higher than the DCN BFs and the DCN BFs shifted lower when the AI BFs were lower than the DCN BFs. The DCN BFs showed no change when the AI and DCN BFs were similar. Moreover, the BF shifts were linearly correlated to the BF differences. Thus, our data suggest that corticofugal modulation of the DCN is also highly specific to frequency information, similar to the corticofugal modulation of the AVCN. The frequency-specificity of corticofugal modulation does not appear limited to the lemniscal ascending pathway.
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Affiliation(s)
- Lingzhi Kong
- Department of Physiology and Pharmacology, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary Calgary, AB, Canada
| | - Colin Xiong
- Department of Physiology and Pharmacology, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary Calgary, AB, Canada
| | - Liang Li
- Department of Psychology, Department of Machine Intelligence, Speech and Hearing Research Center, Key Laboratory on Machine Perception (Ministry of Education), PKU-IDG/McGovern Institute for Brain Research, Peking University Beijing, China
| | - Jun Yan
- Department of Physiology and Pharmacology, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary Calgary, AB, Canada
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23
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The auditory corticocollicular system: molecular and circuit-level considerations. Hear Res 2014; 314:51-9. [PMID: 24911237 DOI: 10.1016/j.heares.2014.05.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 05/22/2014] [Accepted: 05/25/2014] [Indexed: 01/11/2023]
Abstract
We live in a world imbued with a rich mixture of complex sounds. Successful acoustic communication requires the ability to extract meaning from those sounds, even when degraded. One strategy used by the auditory system is to harness high-level contextual cues to modulate the perception of incoming sounds. An ideal substrate for this process is the massive set of top-down projections emanating from virtually every level of the auditory system. In this review, we provide a molecular and circuit-level description of one of the largest of these pathways: the auditory corticocollicular pathway. While its functional role remains to be fully elucidated, activation of this projection system can rapidly and profoundly change the tuning of neurons in the inferior colliculus. Several specific issues are reviewed. First, we describe the complex heterogeneous anatomical organization of the corticocollicular pathway, with particular emphasis on the topography of the pathway. We also review the laminar origin of the corticocollicular projection and discuss known physiological and morphological differences between subsets of corticocollicular cells. Finally, we discuss recent findings about the molecular micro-organization of the inferior colliculus and how it interfaces with corticocollicular termination patterns. Given the assortment of molecular tools now available to the investigator, it is hoped that his review will help guide future research on the role of this pathway in normal hearing.
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24
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Straka MM, Schmitz S, Lim HH. Response features across the auditory midbrain reveal an organization consistent with a dual lemniscal pathway. J Neurophysiol 2014; 112:981-98. [PMID: 25128560 DOI: 10.1152/jn.00008.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The central auditory system has traditionally been divided into lemniscal and nonlemniscal pathways leading from the midbrain through the thalamus to the cortex. This view has served as an organizing principle for studying, modeling, and understanding the encoding of sound within the brain. However, there is evidence that the lemniscal pathway could be further divided into at least two subpathways, each potentially coding for sound in different ways. We investigated whether such an interpretation is supported by the spatial distribution of response features in the central nucleus of the inferior colliculus (ICC), the part of the auditory midbrain assigned to the lemniscal pathway. We recorded responses to pure tone stimuli in the ICC of ketamine-xylazine-anesthetized guinea pigs and used three-dimensional brain reconstruction techniques to map the location of the recording sites. Compared with neurons in caudal-and-medial regions within an isofrequency lamina of the ICC, neurons in rostral-and-lateral regions responded with shorter first-spike latencies with less spiking jitter, shorter durations of spiking responses, a higher proportion of spikes occurring near the onset of the stimulus, lower thresholds, and larger local field potentials with shorter latencies. Further analysis revealed two distinct clusters of response features located in either the caudal-and-medial or the rostral-and-lateral parts of the isofrequency laminae of the ICC. Thus we report substantial differences in coding properties in two regions of the ICC that are consistent with the hypothesis that the lemniscal pathway is made up of at least two distinct subpathways from the midbrain up to the cortex.
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Affiliation(s)
- Małgorzata M Straka
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, Minnesota;
| | - Samuel Schmitz
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, Minnesota
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, Minnesota; Institute for Translational Neuroscience, University of Minnesota, Twin Cities, Minneapolis, Minnesota; and Department of Otolaryngology, University of Minnesota, Twin Cities, Minneapolis, Minnesota
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