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Huang WQ, Sheng H, Wang H, Qi Y, Wang F, Hua Y. Volume electron microscopy reveals age-related ultrastructural differences of globular bush cell axons in mouse central auditory system. Neurobiol Aging 2024; 136:111-124. [PMID: 38342072 DOI: 10.1016/j.neurobiolaging.2024.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
In mammals, thick axonal calibers wrapped with heavy myelin sheaths are prevalent in the auditory nervous system. These features are crucial for fast traveling of nerve impulses with minimal attenuation required for sound signal transmission. In particular, the long-range projections from the cochlear nucleus - the axons of globular bush cells (GBCs) - to the medial nucleus of the trapezoid body (MNTB) are tonotopically organized. However, it remains controversial in gerbils and mice whether structural and functional adaptations are present among the GBC axons targeting different MNTB frequency regions. By means of high-throughput volume electron microscopy, we compared the GBC axons in full-tonotopy-ranged MNTB slices from the C57BL/6 mice at different ages. Our quantification reveals distinct caliber diameter and myelin profile of the GBC axons with endings at lateral and medial MNTB, arguing for modulation of functionally heterogeneous axon subgroups. In addition, we reported axon-specific differences in axon caliber, node of Ranvier, and myelin sheath among juvenile, adult, and old mice, indicating the age-related changes of GBC axon morphology over time. These findings provide structural insight into the maturation and degeneration of GBC axons with frequency tuning across the lifespan of mice.
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Affiliation(s)
- Wen-Qing Huang
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China; Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Central Laboratory, Shanghai Children's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Haibin Sheng
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Haoyu Wang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yumeng Qi
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fangfang Wang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Yunfeng Hua
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China; Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Nabel AL, Teich L, Wohlfrom H, Alexandrova O, Heß M, Pecka M, Grothe B. Development of myelination and axon diameter for fast and precise action potential conductance. Glia 2024; 72:794-808. [PMID: 38174817 DOI: 10.1002/glia.24504] [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: 10/13/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024]
Abstract
Axons of globular bushy cells in the cochlear nucleus convey hyper-accurate signals to the superior olivary complex, the initial site of binaural processing via comparably thick axons and the calyx of the Held synapse. Bushy cell fibers involved in hyper-accurate binaural processing of low-frequency sounds are known to have an unusual internode length-to-axon caliber ratio (L/d) correlating with higher conduction velocity and superior temporal precision of action potentials. How the L/d-ratio develops and what determines this unusual myelination pattern is unclear. Here we describe a gradual developmental transition from very simple to complex, mature nodes of Ranvier on globular bushy cell axons during a 2-week period starting at postnatal day P6/7. The molecular composition of nodes matured successively along the axons from somata to synaptic terminals with morphologically and molecularly mature nodes appearing almost exclusively after hearing onset. Internodal distances are initially coherent with the canonical L/d-ratio of ~100. Several days after hearing onset, however, an over-proportional increase in axon caliber occurs in cells signaling low-frequency sounds which alters their L/d ratio to ~60. Hence, oligodendrocytes initially myelinating axons according to their transient axon caliber but a subsequent differential axon thickening after hearing onset results in the unusual myelination pattern.
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Affiliation(s)
- Alisha L Nabel
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
| | - Laurin Teich
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
- Division of Neurobiology, Faculty of Biology, Munich Cluster for Systems Neurology (SyNergy), Martinsried, Germany
| | - Hilde Wohlfrom
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
| | - Olga Alexandrova
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
| | - Martin Heß
- Division of Systematic Zoology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
| | - Michael Pecka
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-Universität in Munich, Martinsried, Germany
- Division of Neurobiology, Faculty of Biology, Munich Cluster for Systems Neurology (SyNergy), Martinsried, Germany
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Stancu M, Wohlfrom H, Heß M, Grothe B, Leibold C, Kopp-Scheinpflug C. Ambient sound stimulation tunes axonal conduction velocity by regulating radial growth of myelin on an individual, axon-by-axon basis. Proc Natl Acad Sci U S A 2024; 121:e2316439121. [PMID: 38442165 PMCID: PMC10945791 DOI: 10.1073/pnas.2316439121] [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: 09/22/2023] [Accepted: 01/31/2024] [Indexed: 03/07/2024] Open
Abstract
Adaptive myelination is the emerging concept of tuning axonal conduction velocity to the activity within specific neural circuits over time. Sound processing circuits exhibit structural and functional specifications to process signals with microsecond precision: a time scale that is amenable to adjustment in length and thickness of myelin. Increasing activity of auditory axons by introducing sound-evoked responses during postnatal development enhances myelin thickness, while sensory deprivation prevents such radial growth during development. When deprivation occurs during adulthood, myelin thickness was reduced. However, it is unclear whether sensory stimulation adjusts myelination in a global fashion (whole fiber bundles) or whether such adaptation occurs at the level of individual fibers. Using temporary monaural deprivation in mice provided an internal control for a) differentially tracing structural changes in active and deprived fibers and b) for monitoring neural activity in response to acoustic stimulation of the control and the deprived ear within the same animal. The data show that sound-evoked activity increased the number of myelin layers around individual active axons, even when located in mixed bundles of active and deprived fibers. Thicker myelination correlated with faster axonal conduction velocity and caused shorter auditory brainstem response wave VI-I delays, providing a physiologically relevant readout. The lack of global compensation emphasizes the importance of balanced sensory experience in both ears throughout the lifespan of an individual.
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Affiliation(s)
- Mihai Stancu
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
- Munich Cluster for Systems Neurology, Munich81377, Germany
- Graduate School of Systemic Neurosciences, Planegg-Martinsried82152, Germany
| | - Hilde Wohlfrom
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
| | - Martin Heß
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
- Munich Cluster for Systems Neurology, Munich81377, Germany
| | - Christian Leibold
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
- Faculty of Biology, Bernstein Center Freiburg, BrainLinks-BrainTools, University of Freiburg, Freiburg im Breisgau79110, Germany
| | - Conny Kopp-Scheinpflug
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried82152, Germany
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Heller DT, Kolson DR, Brandebura AN, Amick EM, Wan J, Ramadan J, Holcomb PS, Liu S, Deerinck TJ, Ellisman MH, Qian J, Mathers PH, Spirou GA. Astrocyte ensheathment of calyx-forming axons of the auditory brainstem precedes accelerated expression of myelin genes and myelination by oligodendrocytes. J Comp Neurol 2024; 532:e25552. [PMID: 37916792 PMCID: PMC10922096 DOI: 10.1002/cne.25552] [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: 02/28/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 11/03/2023]
Abstract
Early postnatal brain development involves complex interactions among maturing neurons and glial cells that drive tissue organization. We previously analyzed gene expression in tissue from the mouse medial nucleus of the trapezoid body (MNTB) during the first postnatal week to study changes that surround rapid growth of the large calyx of Held (CH) nerve terminal. Here, we present genes that show significant changes in gene expression level during the second postnatal week, a developmental timeframe that brackets the onset of airborne sound stimulation and the early stages of myelination. Gene Ontology analysis revealed that many of these genes are related to the myelination process. Further investigation of these genes using a previously published cell type-specific bulk RNA-Seq data set in cortex and our own single-cell RNA-Seq data set in the MNTB revealed enrichment of these genes in the oligodendrocyte lineage (OL) cells. Combining the postnatal day (P)6-P14 microarray gene expression data with the previously published P0-P6 data provided fine temporal resolution to investigate the initiation and subsequent waves of gene expression related to OL cell maturation and the process of myelination. Many genes showed increasing expression levels between P2 and P6 in patterns that reflect OL cell maturation. Correspondingly, the first myelin proteins were detected by P4. Using a complementary, developmental series of electron microscopy 3D image volumes, we analyzed the temporal progression of axon wrapping and myelination in the MNTB. By employing a combination of established ultrastructural criteria to classify reconstructed early postnatal glial cells in the 3D volumes, we demonstrated for the first time that astrocytes within the mouse MNTB extensively wrap the axons of the growing CH terminal prior to OL cell wrapping and compaction of myelin. Our data revealed significant expression of several myelin genes and enrichment of multiple genes associated with lipid metabolism in astrocytes, which may subserve axon wrapping in addition to myelin formation. The transition from axon wrapping by astrocytes to OL cells occurs rapidly between P4 and P9 and identifies a potential new role of astrocytes in priming calyceal axons for subsequent myelination.
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Affiliation(s)
| | - Douglas R. Kolson
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
| | - Ashley N. Brandebura
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Biochemistry, West Virginia University School of Medicine, Morgantown, WV
| | - Emily M. Amick
- Medical Engineering, University of South Florida, Tampa, FL
| | - Jun Wan
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Jad Ramadan
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
| | - Paul S. Holcomb
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
| | - Sheng Liu
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Thomas J. Deerinck
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA
- Department of Neuroscience, University of California, San Diego, CA
| | - Mark H. Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA
- Department of Neuroscience, University of California, San Diego, CA
| | - Jiang Qian
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Peter H. Mathers
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
- Biochemistry, West Virginia University School of Medicine, Morgantown, WV
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Fischl M, Pederson A, Voglewede R, Cheng H, Drew J, Cadenas LT, Weisz CJ. Fast inhibition slows and desynchronizes mouse auditory efferent neuron activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.21.572886. [PMID: 38313270 PMCID: PMC10836066 DOI: 10.1101/2023.12.21.572886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
The encoding of acoustic stimuli requires precise neuron timing. Auditory neurons in the cochlear nucleus (CN) and brainstem are well-suited for accurate analysis of fast acoustic signals, given their physiological specializations of fast membrane time constants, fast axonal conduction, and reliable synaptic transmission. The medial olivocochlear (MOC) neurons that provide efferent inhibition of the cochlea reside in the ventral brainstem and participate in these fast neural circuits. However, their modulation of cochlear function occurs over time scales of a slower nature. This suggests the presence of mechanisms that restrict MOC inhibition of cochlear function. To determine how monaural excitatory and inhibitory synaptic inputs integrate to affect the timing of MOC neuron activity, we developed a novel in vitro slice preparation ('wedge-slice'). The wedge-slice maintains the ascending auditory nerve root, the entire CN and projecting axons, while preserving the ability to perform visually guided patch-clamp electrophysiology recordings from genetically identified MOC neurons. The 'in vivo-like' timing of the wedge-slice demonstrates that the inhibitory pathway accelerates relative to the excitatory pathway when the ascending circuit is intact, and the CN portion of the inhibitory circuit is precise enough to compensate for reduced precision in later synapses. When combined with machine learning PSC analysis and computational modeling, we demonstrate a larger suppression of MOC neuron activity when the inhibition occurs with in vivo-like timing. This delay of MOC activity may ensure that the MOC system is only engaged by sustained background sounds, preventing a maladaptive hyper-suppression of cochlear activity.
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Affiliation(s)
- Matthew Fischl
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
- Current affiliation: Lafayette College, Neuroscience Program, Easton, PA 18042, USA
| | - Alia Pederson
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
- Current affiliation: The University of Texas at Austin Dell Medical School, Austin, TX 78712, USA
| | - Rebecca Voglewede
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Hui Cheng
- Bioinformatics and Biostatistics Collaboration Core, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Jordan Drew
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
- Current affiliation: Institute for Learning and Brain Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Lester Torres Cadenas
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
| | - Catherine J.C. Weisz
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, USA
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6
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Carr CE, Wang T, Kraemer I, Capshaw G, Ashida G, Köppl C, Kempter R, Kuokkanen PT. Experience-Dependent Plasticity in Nucleus Laminaris of the Barn Owl. J Neurosci 2024; 44:e0940232023. [PMID: 37989591 PMCID: PMC10851688 DOI: 10.1523/jneurosci.0940-23.2023] [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: 05/22/2023] [Revised: 10/12/2023] [Accepted: 11/01/2023] [Indexed: 11/23/2023] Open
Abstract
Interaural time differences (ITDs) are a major cue for sound localization and change with increasing head size. Since the barn owl's head width more than doubles in the month after hatching, we hypothesized that the development of their ITD detection circuit might be modified by experience. To test this, we raised owls with unilateral ear inserts that delayed and attenuated the acoustic signal, and then measured the ITD representation in the brainstem nucleus laminaris (NL) when they were adults. The ITD circuit is composed of delay line inputs to coincidence detectors, and we predicted that plastic changes would lead to shorter delays in the axons from the manipulated ear, and complementary shifts in ITD representation on the two sides. In owls that received ear inserts starting around P14, the maps of ITD shifted in the predicted direction, but only on the ipsilateral side, and only in those tonotopic regions that had not experienced auditory stimulation prior to insertion. The contralateral map did not change. Thus, experience-dependent plasticity of the ITD circuit occurs in NL, and our data suggest that ipsilateral and contralateral delays are independently regulated. As a result, altered auditory input during development leads to long-lasting changes in the representation of ITD.Significance Statement The early life of barn owls is marked by increasing sensitivity to sound, and by increasing ITDs. Their prolonged post-hatch development allowed us to examine the role of altered auditory experience in the development of ITD detection circuits. We raised owls with a unilateral ear insert and found that their maps of ITD were altered by experience, but only in those tonotopic regions ipsilateral to the occluded ear that had not experienced auditory stimulation prior to insertion. This experience-induced plasticity allows the sound localization circuits to be customized to individual characteristics, such as the size of the head, and potentially to compensate for imbalanced hearing sensitivities between the left and right ears.
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Affiliation(s)
- Catherine E Carr
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Tiffany Wang
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Ira Kraemer
- Department of Biology, University of Maryland College Park, College Park, MD 20742
| | - Grace Capshaw
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218
| | - Go Ashida
- Department of Neuroscience, School of Medicine and Health Sciences, Research Center for Neurosensory Sciences and Cluster of Excellence "Hearing4all" Carl von Ossietzky University, 26129 Oldenburg, Germany
| | - Christine Köppl
- Department of Neuroscience, School of Medicine and Health Sciences, Research Center for Neurosensory Sciences and Cluster of Excellence "Hearing4all" Carl von Ossietzky University, 26129 Oldenburg, Germany
| | - Richard Kempter
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
- Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
| | - Paula T Kuokkanen
- Department of Biology, University of Maryland College Park, College Park, MD 20742
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Yu Q, Gao J, Wei J, Li J, Tan KC, Huang T. Improving Multispike Learning With Plastic Synaptic Delays. IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2023; 34:10254-10265. [PMID: 35442893 DOI: 10.1109/tnnls.2022.3165527] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Emulating the spike-based processing in the brain, spiking neural networks (SNNs) are developed and act as a promising candidate for the new generation of artificial neural networks that aim to produce efficient cognitions as the brain. Due to the complex dynamics and nonlinearity of SNNs, designing efficient learning algorithms has remained a major difficulty, which attracts great research attention. Most existing ones focus on the adjustment of synaptic weights. However, other components, such as synaptic delays, are found to be adaptive and important in modulating neural behavior. How could plasticity on different components cooperate to improve the learning of SNNs remains as an interesting question. Advancing our previous multispike learning, we propose a new joint weight-delay plasticity rule, named TDP-DL, in this article. Plastic delays are integrated into the learning framework, and as a result, the performance of multispike learning is significantly improved. Simulation results highlight the effectiveness and efficiency of our TDP-DL rule compared to baseline ones. Moreover, we reveal the underlying principle of how synaptic weights and delays cooperate with each other through a synthetic task of interval selectivity and show that plastic delays can enhance the selectivity and flexibility of neurons by shifting information across time. Due to this capability, useful information distributed away in the time domain can be effectively integrated for a better accuracy performance, as highlighted in our generalization tasks of the image, speech, and event-based object recognitions. Our work is thus valuable and significant to improve the performance of spike-based neuromorphic computing.
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8
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Carr CE, Wang T, Kraemer I, Capshaw G, Ashida G, Koeppl C, Kempter R, Kuokkanen PT. Experience-Dependent Plasticity in Nucleus Laminaris of the Barn Owl. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526884. [PMID: 36778252 PMCID: PMC9915572 DOI: 10.1101/2023.02.02.526884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Barn owls experience increasing interaural time differences (ITDs) during development, because their head width more than doubles in the month after hatching. We therefore hypothesized that their ITD detection circuit might be modified by experience. To test this, we raised owls with unilateral ear inserts that delayed and attenuated the acoustic signal, then measured the ITD representation in the brainstem nucleus laminaris (NL) when they were adult. The ITD circuit is composed of delay line inputs to coincidence detectors, and we predicted that plastic changes would lead to shorter delays in the axons from the manipulated ear, and complementary shifts in ITD representation on the two sides. In owls that received ear inserts starting around P14, the maps of ITD shifted in the predicted direction, but only on the ipsilateral side, and only in those tonotopic regions that had not experienced auditory stimulation prior to insertion. The contralateral map did not change. Experience-dependent plasticity of the ITD circuit occurs in NL, and our data suggest that ipsilateral and contralateral delays are independently regulated. Thus, altered auditory input during development leads to long-lasting changes in the representation of ITD.
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9
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de Cheveigné A. Why is the perceptual octave stretched? An account based on mismatched time constants within the auditory brainstem. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:2600. [PMID: 37129672 DOI: 10.1121/10.0017978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/12/2023] [Indexed: 05/03/2023]
Abstract
This paper suggests an explanation for listeners' greater tolerance to positive than negative mistuning of the higher tone within an octave pair. It hypothesizes a neural circuit tuned to cancel the lower tone that also cancels the higher tone if that tone is in tune. Imperfect cancellation is the cue to mistuning of the octave. The circuit involves two neural pathways, one delayed with respect to the other, that feed a coincidence-sensitive neuron via excitatory and inhibitory synapses. A mismatch between the time constants of these two synapses results in an asymmetry in sensitivity to mismatch. Specifically, if the time constant of the delayed pathway is greater than that of the direct pathway, there is a greater tolerance to positive mistuning than to negative mistuning. The model is directly applicable to the harmonic octave (concurrent tones) but extending it to the melodic octave (successive tones) requires additional assumptions that are discussed. The paper reviews evidence from auditory psychophysics and physiology in favor-or against-this explanation.
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Affiliation(s)
- Alain de Cheveigné
- Laboratoire des Systèmes Perceptifs, Unité Mixte de Recherche 8248, Centre National de la Recherche Scientifique, Paris, France
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10
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Kladisios N, Wicke KD, Pätz-Warncke C, Felmy F. Species-Specific Adaptation for Ongoing High-Frequency Action Potential Generation in MNTB Neurons. J Neurosci 2023; 43:2714-2729. [PMID: 36898837 PMCID: PMC10089249 DOI: 10.1523/jneurosci.2320-22.2023] [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: 12/21/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/12/2023] Open
Abstract
Comparative analysis of evolutionarily conserved neuronal circuits between phylogenetically distant mammals highlights the relevant mechanisms and specific adaptations to information processing. The medial nucleus of the trapezoid body (MNTB) is a conserved mammalian auditory brainstem nucleus relevant for temporal processing. While MNTB neurons have been extensively investigated, a comparative analysis of phylogenetically distant mammals and the spike generation is missing. To understand the suprathreshold precision and firing rate, we examined the membrane, voltage-gated ion channel and synaptic properties in Phyllostomus discolor (bat) and in Meriones unguiculatus (rodent) of either sex. Between the two species, the membrane properties of MNTB neurons were similar at rest with only minor differences, while larger dendrotoxin (DTX)-sensitive potassium currents were found in gerbils. Calyx of Held-mediated EPSCs were smaller and frequency dependence of short-term plasticity (STP) less pronounced in bats. Simulating synaptic train stimulations in dynamic clamp revealed that MNTB neurons fired with decreasing success rate near conductance threshold and at increasing stimulation frequency. Driven by STP-dependent conductance decrease, the latency of evoked action potentials increased during train stimulations. The spike generator showed a temporal adaptation at the beginning of train stimulations that can be explained by sodium current inactivation. Compared with gerbils, the spike generator of bats sustained higher frequency input-output functions and upheld the same temporal precision. Our data mechanistically support that MNTB input-output functions in bats are suited to sustain precise high-frequency rates, while for gerbils, temporal precision appears more relevant and an adaptation to high output-rates can be spared.SIGNIFICANCE STATEMENT Neurons in the mammalian medial nucleus of the trapezoid body (MNTB) convey precise, faithful inhibition vital for binaural hearing and gap detection. The MNTB's structure and function appear evolutionarily well conserved. We compared the cellular physiology of MNTB neurons in bat and gerbil. Because of their adaptations to echolocation or low frequency hearing both species are model systems for hearing research, yet with largely overlapping hearing ranges. We find that bat neurons sustain information transfer with higher ongoing rates and precision based on synaptic and biophysical differences in comparison to gerbils. Thus, even in evolutionarily conserved circuits species-specific adaptations prevail, highlighting the importance for comparative research to differentiate general circuit functions and their specific adaptations.
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Affiliation(s)
- Nikolaos Kladisios
- Institute of Zoology, University of Veterinary Medicine Hannover Foundation 30559 Hannover, Germany
- Hannover Graduate School for Neurosciences, Infection Medicine and Veterinary Sciences (HGNI), 30559 Hannover, Germany
| | - Kathrin D Wicke
- Institute of Zoology, University of Veterinary Medicine Hannover Foundation 30559 Hannover, Germany
- Hannover Graduate School for Neurosciences, Infection Medicine and Veterinary Sciences (HGNI), 30559 Hannover, Germany
| | - Christina Pätz-Warncke
- Institute of Zoology, University of Veterinary Medicine Hannover Foundation 30559 Hannover, Germany
| | - Felix Felmy
- Institute of Zoology, University of Veterinary Medicine Hannover Foundation 30559 Hannover, Germany
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11
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Valderrama JT, de la Torre A, McAlpine D. The hunt for hidden hearing loss in humans: From preclinical studies to effective interventions. Front Neurosci 2022; 16:1000304. [PMID: 36188462 PMCID: PMC9519997 DOI: 10.3389/fnins.2022.1000304] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022] Open
Abstract
Many individuals experience hearing problems that are hidden under a normal audiogram. This not only impacts on individual sufferers, but also on clinicians who can offer little in the way of support. Animal studies using invasive methodologies have developed solid evidence for a range of pathologies underlying this hidden hearing loss (HHL), including cochlear synaptopathy, auditory nerve demyelination, elevated central gain, and neural mal-adaptation. Despite progress in pre-clinical models, evidence supporting the existence of HHL in humans remains inconclusive, and clinicians lack any non-invasive biomarkers sensitive to HHL, as well as a standardized protocol to manage hearing problems in the absence of elevated hearing thresholds. Here, we review animal models of HHL as well as the ongoing research for tools with which to diagnose and manage hearing difficulties associated with HHL. We also discuss new research opportunities facilitated by recent methodological tools that may overcome a series of barriers that have hampered meaningful progress in diagnosing and treating of HHL.
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Affiliation(s)
- Joaquin T. Valderrama
- National Acoustic Laboratories, Sydney, NSW, Australia
- Department of Linguistics, Macquarie University Hearing, Macquarie University, Sydney, NSW, Australia
- *Correspondence: Joaquin T. Valderrama, ;
| | - Angel de la Torre
- Department of Signal Theory, Telematics and Communications, University of Granada, Granada, Spain
- Research Centre for Information and Communications Technologies (CITIC-UGR), University of Granada, Granada, Spain
| | - David McAlpine
- Department of Linguistics, Macquarie University Hearing, Macquarie University, Sydney, NSW, Australia
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12
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McCullagh EA, Poleg S, Stich D, Moldovan R, Klug A. Coherent Anti-Stokes Raman Spectroscopy (CARS) Application for Imaging Myelination in Brain Slices. J Vis Exp 2022:10.3791/64013. [PMID: 35938838 PMCID: PMC9484306 DOI: 10.3791/64013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024] Open
Abstract
Coherent anti-Stokes Raman spectroscopy (CARS) is a technique classically employed by chemists and physicists to produce a coherent signal of signature vibrations of molecules. However, these vibrational signatures are also characteristic of molecules within anatomical tissue such as the brain, making it increasingly useful and applicable for Neuroscience applications. For example, CARS can measure lipids by specifically exciting chemical bonds within these molecules, allowing for quantification of different aspects of tissue, such as myelin involved in neurotransmission. In addition, compared to other techniques typically used to quantify myelin, CARS can also be set up to be compatible with immunofluorescent techniques, allowing for co-labeling with other markers such as sodium channels or other components of synaptic transmission. Myelination changes are an inherently important mechanism in demyelinating diseases such as multiple sclerosis or other neurological conditions such as Fragile X Syndrome or autism spectrum disorders is an emerging area of research. In conclusion, CARS can be utilized in innovative ways to answer pressing questions in Neuroscience and provide evidence for underlying mechanisms related to many different neurological conditions.
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Affiliation(s)
| | - Shani Poleg
- Department of Physiology and Biophysics, University of Colorado Anschutz
| | - Dominik Stich
- Advanced Light Microscopy Core, University of Colorado Anschutz
| | - Radu Moldovan
- Advanced Light Microscopy Core, University of Colorado Anschutz
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz
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13
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Curnow E, Wang Y. New Animal Models for Understanding FMRP Functions and FXS Pathology. Cells 2022; 11:1628. [PMID: 35626665 PMCID: PMC9140010 DOI: 10.3390/cells11101628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022] Open
Abstract
Fragile X encompasses a range of genetic conditions, all of which result as a function of changes within the FMR1 gene and abnormal production and/or expression of the FMR1 gene products. Individuals with Fragile X syndrome (FXS), the most common heritable form of intellectual disability, have a full-mutation sequence (>200 CGG repeats) which brings about transcriptional silencing of FMR1 and loss of FMR protein (FMRP). Despite considerable progress in our understanding of FXS, safe, effective, and reliable treatments that either prevent or reduce the severity of the FXS phenotype have not been approved. While current FXS animal models contribute their own unique understanding to the molecular, cellular, physiological, and behavioral deficits associated with FXS, no single animal model is able to fully recreate the FXS phenotype. This review will describe the status and rationale in the development, validation, and utility of three emerging animal model systems for FXS, namely the nonhuman primate (NHP), Mongolian gerbil, and chicken. These developing animal models will provide a sophisticated resource in which the deficits in complex functions of perception, action, and cognition in the human disorder are accurately reflected and aid in the successful translation of novel therapeutics and interventions to the clinic setting.
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Affiliation(s)
- Eliza Curnow
- REI Division, Department of ObGyn, University of Washington, Seattle, WA 98195, USA
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195, USA
| | - Yuan Wang
- Program in Neuroscience, Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA
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14
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Hu H, Klug J, Dietz M. Simulation of ITD-Dependent Single-Neuron Responses Under Electrical Stimulation and with Amplitude-Modulated Acoustic Stimuli. J Assoc Res Otolaryngol 2022; 23:535-550. [PMID: 35334001 PMCID: PMC9437183 DOI: 10.1007/s10162-021-00823-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 11/03/2021] [Indexed: 11/30/2022] Open
Abstract
Interaural time difference (ITD) sensitivity with cochlear implant stimulation is remarkably similar to envelope ITD sensitivity using conventional acoustic stimulation. This holds true for human perception, as well as for neural response rates recorded in the inferior colliculus of several mammalian species. We hypothesize that robust excitatory-inhibitory (EI) interaction is the dominant mechanism. Therefore, we connected the same single EI-model neuron to either a model of the normal acoustic auditory periphery or to a model of the electrically stimulated auditory nerve. The model captured most features of the experimentally obtained response properties with electric stimulation, such as the shape of rate-ITD functions, the dependence on stimulation level, and the pulse rate or modulation-frequency dependence. Rate-ITD functions with high-rate, amplitude-modulated electric stimuli were very similar to their acoustic counterparts. Responses obtained with unmodulated electric pulse trains most resembled acoustic filtered clicks. The fairly rapid decline of ITD sensitivity at rates above 300 pulses or cycles per second is correctly simulated by the 3.1-ms time constant of the inhibitory post-synaptic conductance. As the model accounts for these basic properties, it is expected to help in understanding and quantifying the binaural hearing abilities with electric stimulation when integrated in bigger simulation frameworks.
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Affiliation(s)
- Hongmei Hu
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany.
| | - Jonas Klug
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany
| | - Mathias Dietz
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany
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15
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Li BZ, Pun SH, Vai MI, Lei TC, Klug A. Predicting the Influence of Axon Myelination on Sound Localization Precision Using a Spiking Neural Network Model of Auditory Brainstem. Front Neurosci 2022; 16:840983. [PMID: 35360169 PMCID: PMC8964079 DOI: 10.3389/fnins.2022.840983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/18/2022] [Indexed: 01/12/2023] Open
Abstract
Spatial hearing allows animals to rapidly detect and localize auditory events in the surrounding environment. The auditory brainstem plays a central role in processing and extracting binaural spatial cues through microsecond-precise binaural integration, especially for detecting interaural time differences (ITDs) of low-frequency sounds at the medial superior olive (MSO). A series of mechanisms exist in the underlying neural circuits for preserving accurate action potential timing across multiple fibers, synapses and nuclei along this pathway. One of these is the myelination of afferent fibers that ensures reliable and temporally precise action potential propagation in the axon. There are several reports of fine-tuned myelination patterns in the MSO circuit, but how specifically myelination influences the precision of sound localization remains incompletely understood. Here we present a spiking neural network (SNN) model of the Mongolian gerbil auditory brainstem with myelinated axons to investigate whether different axon myelination thicknesses alter the sound localization process. Our model demonstrates that axon myelin thickness along the contralateral pathways can substantially modulate ITD detection. Furthermore, optimal ITD sensitivity is reached when the MSO receives contralateral inhibition via thicker myelinated axons compared to contralateral excitation, a result that is consistent with previously reported experimental observations. Our results suggest specific roles of axon myelination for extracting temporal dynamics in ITD decoding, especially in the pathway of the contralateral inhibition.
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Affiliation(s)
- Ben-Zheng Li
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States,Department of Electrical Engineering, University of Colorado, Denver, Denver, CO, United States,State Key Laboratory of Analog and Mixed Signal Very-Large-Scale Integration (VLSI), University of Macau, Taipa, Macau SAR, China,Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macau SAR, China
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed Signal Very-Large-Scale Integration (VLSI), University of Macau, Taipa, Macau SAR, China
| | - Mang I. Vai
- State Key Laboratory of Analog and Mixed Signal Very-Large-Scale Integration (VLSI), University of Macau, Taipa, Macau SAR, China,Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macau SAR, China
| | - Tim C. Lei
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States,Department of Electrical Engineering, University of Colorado, Denver, Denver, CO, United States
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States,*Correspondence: Achim Klug,
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16
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Lucas A, Poleg S, Klug A, McCullagh EA. Myelination Deficits in the Auditory Brainstem of a Mouse Model of Fragile X Syndrome. Front Neurosci 2021; 15:772943. [PMID: 34858133 PMCID: PMC8632548 DOI: 10.3389/fnins.2021.772943] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
Auditory symptoms are one of the most frequent sensory issues described in people with Fragile X Syndrome (FXS), the most common genetic form of intellectual disability. However, the mechanisms that lead to these symptoms are under explored. In this study, we examined whether there are defects in myelination in the auditory brainstem circuitry. Specifically, we studied myelinated fibers that terminate in the Calyx of Held, which encode temporally precise sound arrival time, and are some of the most heavily myelinated axons in the brain. We measured anatomical myelination characteristics using coherent anti-stokes Raman spectroscopy (CARS) and electron microscopy (EM) in a FXS mouse model in the medial nucleus of the trapezoid body (MNTB) where the Calyx of Held synapses. We measured number of mature oligodendrocytes (OL) and oligodendrocyte precursor cells (OPCs) to determine if changes in myelination were due to changes in the number of myelinating or immature glial cells. The two microscopy techniques (EM and CARS) showed a decrease in fiber diameter in FXS mice. Additionally, EM results indicated reductions in myelin thickness and axon diameter, and an increase in g-ratio, a measure of structural and functional myelination. Lastly, we showed an increase in both OL and OPCs in MNTB sections of FXS mice suggesting that the myelination phenotype is not due to an overall decrease in number of myelinating OLs. This is the first study to show that a myelination defects in the auditory brainstem that may underly auditory phenotypes in FXS.
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Affiliation(s)
- Alexandra Lucas
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Shani Poleg
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Elizabeth A McCullagh
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States
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17
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Li BZ, Pun SH, Vai MI, Klug A, Lei TC. Axonal Conduction Delay Shapes the Precision of the Spatial Hearing in A Spiking Neural Network Model of Auditory Brainstem. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:4238-4241. [PMID: 34892159 DOI: 10.1109/embc46164.2021.9629932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
One method by which the mammalian sound localization pathway localizes sound sources is by analyzing the microsecond-level difference between the arrival times of a sound at the two ears. However, how the neural circuits in the auditory brainstem precisely integrate signals from the two ears, and what the underlying mechanisms are, remains to be understood. Recent studies have reported that variations of axon myelination in the auditory brainstem produces various axonal conduction velocities and sophisticated temporal dynamics, which have not been well characterized in most existing models of sound localization circuits. Here, we present a spiking neural network model of the auditory brainstem to investigate how axon myelinations affect the precision of sound localization. Sound waves with different interaural time differences (ITDs) are encoded and used as stimuli, and the axon properties in the network are adjusted, and the corresponding axonal conduction delays are computed with a multi-compartment axon model. Through the simulation, the sensitivity of ITD perception varies with the myelin thickness of axons in the contralateral input pathways to the medial superior olive (MSO). The ITD perception becomes more precise when the contralateral inhibitory input propagates faster than the contralateral excitatory input. These results indicate that axon myelination and contralateral spike timing influence spatial hearing perception.
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18
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Yuan T, Shao Y, Zhou X, Liu Q, Zhu Z, Zhou B, Dong Y, Stephanopoulos N, Gui S, Yan H, Liu D. Highly Permeable DNA Supramolecular Hydrogel Promotes Neurogenesis and Functional Recovery after Completely Transected Spinal Cord Injury. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102428. [PMID: 34296471 DOI: 10.1002/adma.202102428] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/01/2021] [Indexed: 06/13/2023]
Abstract
Regeneration after severe spinal cord injury cannot occur naturally in mammals. Transplanting stem cells to the injury site is a highly promising method, but it faces many challenges because it relies heavily on the microenvironment provided by both the lesion site and delivery material. Although mechanical properties, biocompatibility, and biodegradability of delivery materials have been extensively explored, their permeability has rarely been recognized. Here, a DNA hydrogel is designed with extremely high permeability to repair a 2 mm spinal cord gap in Sprague-Dawley rats. The rats recover basic hindlimb function with detectable motor-evoked potentials, and a renascent neural network is formed via the proliferation and differentiation of both implanted and endogenous stem cells. The signal at the lesion area is conveyed by, on average, 15 newly formed synapses. This hydrogel system offers great potential in clinical trials. Further, it should be easily adaptable to other tissue regeneration applications.
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Affiliation(s)
- Taoyang Yuan
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100071, China
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100071, China
| | - Yu Shao
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Xu Zhou
- Center for Molecular Design and Biomimetics, The Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85281, USA
| | - Qian Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100071, China
| | - Zhichao Zhu
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Bini Zhou
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Yuanchen Dong
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Nicholas Stephanopoulos
- Center for Molecular Design and Biomimetics, The Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85281, USA
| | - Songbai Gui
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100071, China
| | - Hao Yan
- Center for Molecular Design and Biomimetics, The Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85281, USA
| | - Dongsheng Liu
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing, 100084, China
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19
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Mazuir E, Fricker D, Sol-Foulon N. Neuron-Oligodendrocyte Communication in Myelination of Cortical GABAergic Cells. Life (Basel) 2021; 11:216. [PMID: 33803153 PMCID: PMC7999565 DOI: 10.3390/life11030216] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 11/17/2022] Open
Abstract
Axonal myelination by oligodendrocytes increases the speed and reliability of action potential propagation, and so plays a pivotal role in cortical information processing. The extent and profile of myelination vary between different cortical layers and groups of neurons. Two subtypes of cortical GABAergic neurons are myelinated: fast-spiking parvalbumin-expressing cells and somatostatin-containing cells. The expression of pre-nodes on the axon of these inhibitory cells before myelination illuminates communication between oligodendrocytes and neurons. We explore the consequences of myelination for action potential propagation, for patterns of neuronal connectivity and for the expression of behavioral plasticity.
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Affiliation(s)
- Elisa Mazuir
- Inserm, CNRS, Paris Brain Institute, ICM, Sorbonne University, Pitié-Salpêtrière Hospital, F-75013 Paris, France
| | - Desdemona Fricker
- CNRS UMR 8002, Integrative Neuroscience and Cognition Center, Université de Paris, F-75006 Paris, France
| | - Nathalie Sol-Foulon
- Inserm, CNRS, Paris Brain Institute, ICM, Sorbonne University, Pitié-Salpêtrière Hospital, F-75013 Paris, France
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20
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Kohrman DC, Borges BC, Cassinotti LR, Ji L, Corfas G. Axon-glia interactions in the ascending auditory system. Dev Neurobiol 2021; 81:546-567. [PMID: 33561889 DOI: 10.1002/dneu.22813] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/25/2020] [Accepted: 02/05/2021] [Indexed: 11/09/2022]
Abstract
The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.
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Affiliation(s)
- David C Kohrman
- Department of Otolaryngology - Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
| | - Beatriz C Borges
- Department of Otolaryngology - Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
| | - Luis R Cassinotti
- Department of Otolaryngology - Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
| | - Lingchao Ji
- Department of Otolaryngology - Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
| | - Gabriel Corfas
- Department of Otolaryngology - Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI, USA
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21
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Moore S, Meschkat M, Ruhwedel T, Trevisiol A, Tzvetanova ID, Battefeld A, Kusch K, Kole MHP, Strenzke N, Möbius W, de Hoz L, Nave KA. A role of oligodendrocytes in information processing. Nat Commun 2020; 11:5497. [PMID: 33127910 PMCID: PMC7599337 DOI: 10.1038/s41467-020-19152-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Myelinating oligodendrocytes enable fast propagation of action potentials along the ensheathed axons. In addition, oligodendrocytes play diverse non-canonical roles including axonal metabolic support and activity-dependent myelination. An open question remains whether myelination also contributes to information processing in addition to speeding up conduction velocity. Here, we analyze the role of myelin in auditory information processing using paradigms that are also good predictors of speech understanding in humans. We compare mice with different degrees of dysmyelination using acute multiunit recordings in the auditory cortex, in combination with behavioral readouts. We find complex alterations of neuronal responses that reflect fatigue and temporal acuity deficits. We observe partially discriminable but similar deficits in well myelinated mice in which glial cells cannot fully support axons metabolically. We suggest a model in which myelination contributes to sustained stimulus perception in temporally complex paradigms, with a role of metabolically active oligodendrocytes in cortical information processing.
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Affiliation(s)
- Sharlen Moore
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- International Max Planck Research School for Neurosciences, Göttingen, Germany
- Göttingen Graduate Center for Neurosciences, Biophysics and Molecular Biosciences, Georg-August-Universität Göttingen, Göttingen, Germany
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, USA
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Andrea Trevisiol
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Iva D Tzvetanova
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Section of Pharmacology, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Arne Battefeld
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maarten H P Kole
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, University of Utrecht, Utrecht, The Netherlands
| | - Nicola Strenzke
- Institute for Auditory Neuroscience, University Medical Center, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
- Charité Medical University, Neuroscience Research Center, Berlin, Germany.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
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22
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Abstract
During development and adulthood, the normal activity of the auditory nerve plays a critical role in the maintenance of both fundamental structural, molecular, and functional parameters of auditory nerve synapses, and the postsynaptic excitatory or inhibitory neurons within the cochlear nucleus (CN). In addition, normal activity within the synaptic circuits of the CN is key to developing and maintaining appropriate synapse connectivity as well as the initiation of binaural sound processing in the superior olivary complex (SOC). Development plays a critical role in the proper neuronal connectivity and establishes a topographic map along the entire auditory pathway. Furthermore, evidence shows that neurons and synaptic circuits in the auditory brainstem are not hard-wired, but instead are plastic in response to hearing deficits. Whether this plasticity in response to hearing loss is compensatory or pathological is still unknown.
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Affiliation(s)
- María Eulalia Rubio
- Departments of Neurobiology and Otolaryngology, University of Pittsburgh, School of Medicine, BST3 Building, room #10016, 3501 Fifth Venue, Pittsburgh, PA, 15261
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23
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Snaidero N, Schifferer M, Mezydlo A, Zalc B, Kerschensteiner M, Misgeld T. Myelin replacement triggered by single-cell demyelination in mouse cortex. Nat Commun 2020; 11:4901. [PMID: 32994410 PMCID: PMC7525521 DOI: 10.1038/s41467-020-18632-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022] Open
Abstract
Myelin, rather than being a static insulator of axons, is emerging as an active participant in circuit plasticity. This requires precise regulation of oligodendrocyte numbers and myelination patterns. Here, by devising a laser ablation approach of single oligodendrocytes, followed by in vivo imaging and correlated ultrastructural reconstructions, we report that in mouse cortex demyelination as subtle as the loss of a single oligodendrocyte can trigger robust cell replacement and remyelination timed by myelin breakdown. This results in reliable reestablishment of the original myelin pattern along continuously myelinated axons, while in parallel, patchy isolated internodes emerge on previously unmyelinated axons. Therefore, in mammalian cortex, internodes along partially myelinated cortical axons are typically not reestablished, suggesting that the cues that guide patchy myelination are not preserved through cycles of de- and remyelination. In contrast, myelin sheaths forming continuous patterns show remarkable homeostatic resilience and remyelinate with single axon precision.
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Affiliation(s)
- Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technische Universität München, 80802, Munich, Germany.
- German Center for Neurodegenerative Diseases (DZNE), 81377, Munich, Germany.
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, 81377, Munich, Germany.
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, 82152, Martinsried, Germany.
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), 81377, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Aleksandra Mezydlo
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, 81377, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, 82152, Martinsried, Germany
| | - Bernard Zalc
- Inserm, CNRS, Institut du Cerveau, Pitié-Salpêtrière Hospital, Sorbonne Université, 75013, Paris, France
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, 81377, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, 82152, Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, 80802, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), 81377, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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24
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Torres Cadenas L, Fischl MJ, Weisz CJC. Synaptic Inhibition of Medial Olivocochlear Efferent Neurons by Neurons of the Medial Nucleus of the Trapezoid Body. J Neurosci 2020; 40:509-525. [PMID: 31719165 PMCID: PMC6961997 DOI: 10.1523/jneurosci.1288-19.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 02/08/2023] Open
Abstract
Medial olivocochlear (MOC) efferent neurons in the brainstem comprise the final stage of descending control of the mammalian peripheral auditory system through axon projections to the cochlea. MOC activity adjusts cochlear gain and frequency tuning, and protects the ear from acoustic trauma. The neuronal pathways that activate and modulate the MOC somata in the brainstem to drive these cochlear effects are poorly understood. Evidence suggests that MOC neurons are primarily excited by sound stimuli in a three-neuron activation loop from the auditory nerve via an intermediate neuron in the cochlear nucleus. Anatomical studies suggest that MOC neurons receive diverse synaptic inputs, but the functional effect of additional synaptic influences on MOC neuron responses is unknown. Here we use patch-clamp electrophysiological recordings from identified MOC neurons in brainstem slices from mice of either sex to demonstrate that in addition to excitatory glutamatergic synapses, MOC neurons receive inhibitory GABAergic and glycinergic synaptic inputs. These synapses are activated by electrical stimulation of axons near the medial nucleus of the trapezoid body (MNTB). Focal glutamate uncaging confirms MNTB neurons as a source of inhibitory synapses onto MOC neurons. MNTB neurons inhibit MOC action potentials, but this effect depresses with repeat activation. This work identifies a new pathway of connectivity between brainstem auditory neurons and indicates that MOC neurons are both excited and inhibited by sound stimuli received at the same ear. The pathway depression suggests that the effect of MNTB inhibition of MOC neurons diminishes over the course of a sustained sound.SIGNIFICANCE STATEMENT Medial olivocochlear (MOC) neurons are the final stage of descending control of the mammalian auditory system and exert influence on cochlear mechanics to modulate perception of acoustic stimuli. The brainstem pathways that drive MOC function are poorly understood. Here we show for the first time that MOC neurons are inhibited by neurons of the MNTB, which may suppress the effects of MOC activity on the cochlea.
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Affiliation(s)
- Lester Torres Cadenas
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland 20892
| | - Matthew J Fischl
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland 20892
| | - Catherine J C Weisz
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland 20892
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25
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Bullmann T, Radivojevic M, Huber ST, Deligkaris K, Hierlemann A, Frey U. Large-Scale Mapping of Axonal Arbors Using High-Density Microelectrode Arrays. Front Cell Neurosci 2019; 13:404. [PMID: 31555099 PMCID: PMC6742744 DOI: 10.3389/fncel.2019.00404] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/20/2019] [Indexed: 12/30/2022] Open
Abstract
Understanding the role of axons in neuronal information processing is a fundamental task in neuroscience. Over the last years, sophisticated patch-clamp investigations have provided unexpected and exciting data on axonal phenomena and functioning, but there is still a need for methods to investigate full axonal arbors at sufficient throughput. Here, we present a new method for the simultaneous mapping of the axonal arbors of a large number of individual neurons, which relies on their extracellular signals that have been recorded with high-density microelectrode arrays (HD-MEAs). The segmentation of axons was performed based on the local correlation of extracellular signals. Comparison of the results with both, ground truth and receiver operator characteristics, shows that the new segmentation method outperforms previously used methods. Using a standard HD-MEA, we mapped the axonal arbors of 68 neurons in <6 h. The fully automated method can be extended to new generations of HD-MEAs with larger data output and is estimated to provide data of axonal arbors of thousands of neurons within recording sessions of a few hours.
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Affiliation(s)
- Torsten Bullmann
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Graduate School of Informatics, Kyoto University, Kyoto, Japan.,Carl Ludwig Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Milos Radivojevic
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Kosmas Deligkaris
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Andreas Hierlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Urs Frey
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,MaxWell Biosystems AG, Basel, Switzerland
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26
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Zorio DAR, Monsma S, Sanes DH, Golding NL, Rubel EW, Wang Y. De novo sequencing and initial annotation of the Mongolian gerbil (Meriones unguiculatus) genome. Genomics 2019; 111:441-449. [PMID: 29526484 PMCID: PMC6129228 DOI: 10.1016/j.ygeno.2018.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/26/2018] [Accepted: 03/01/2018] [Indexed: 12/28/2022]
Abstract
The Mongolian gerbil (Meriones unguiculatus) is a member of the rodent family that displays several features not found in mice or rats, including sensory specializations and social patterns more similar to those in humans. These features have made gerbils a valuable animal for research studies of auditory and visual processing, brain development, learning and memory, and neurological disorders. Here, we report the whole gerbil annotated genome sequence, and identify important similarities and differences to the human and mouse genomes. We further analyze the chromosomal structure of eight genes with high relevance for controlling neural signaling and demonstrate a high degree of homology between these genes in mouse and gerbil. This homology increases the likelihood that individual genes can be rapidly identified in gerbil and used for genetic manipulations. The availability of the gerbil genome provides a foundation for advancing our knowledge towards understanding evolution, behavior and neural function in mammals. ACCESSION NUMBER: The Whole Genome Shotgun sequence data from this project has been deposited at DDBJ/ENA/GenBank under the accession NHTI00000000. The version described in this paper is version NHTI01000000. The fragment reads, and mate pair reads have been deposited in the Sequence Read Archive under BioSample accession SAMN06897401.
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Affiliation(s)
- Diego A R Zorio
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA.
| | | | - Dan H Sanes
- Center for Neural Science, New York University, New York, NY, USA
| | - Nace L Golding
- University of Texas at Austin, Department of Neuroscience, Center for Learning and Memory, Austin, TX, USA
| | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA, USA
| | - Yuan Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA; Program in Neuroscience, Florida State University, Tallahassee, FL, USA.
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27
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Effects of lifetime noise exposure on the middle-age human auditory brainstem response, tinnitus and speech-in-noise intelligibility. Hear Res 2018; 365:36-48. [DOI: 10.1016/j.heares.2018.06.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/25/2018] [Accepted: 06/08/2018] [Indexed: 01/03/2023]
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28
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Sun L, Zhang Y, Hwang G, Jiang J, Kim D, Eshete YA, Zhao R, Yang H. Synaptic Computation Enabled by Joule Heating of Single-Layered Semiconductors for Sound Localization. NANO LETTERS 2018; 18:3229-3234. [PMID: 29668290 DOI: 10.1021/acs.nanolett.8b00994] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Synaptic computation, which is vital for information processing and decision making in neural networks, has remained technically challenging to be demonstrated without using numerous transistors and capacitors, though significant efforts have been made to emulate the biological synaptic transmission such as short-term and long-term plasticity and memory. Here, we report synaptic computation based on Joule heating and versatile doping induced metal-insulator transition in a scalable monolayer-molybdenum disulfide (MoS2) device with a biologically comparable energy consumption (∼10 fJ). A circuit with our tunable excitatory and inhibitory synaptic devices demonstrates a key function for realizing the most precise temporal computation in the human brain, sound localization: detecting an interaural time difference by suppressing sound intensity- or frequency-dependent synaptic connectivity. This Letter opens a way to implement synaptic computing in neuromorphic applications, overcoming the limitation of scalability and power consumption in conventional CMOS-based neuromorphic devices.
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Affiliation(s)
- Linfeng Sun
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Yishu Zhang
- Singapore University of Technology & Design , 8 Somapah Road , 487372 , Singapore
| | - Geunwoo Hwang
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Jinbao Jiang
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
- IBS Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Dohyun Kim
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Yonas Assefa Eshete
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
| | - Rong Zhao
- Singapore University of Technology & Design , 8 Somapah Road , 487372 , Singapore
| | - Heejun Yang
- Department of Energy Science , Sungkyunkwan University , Suwon 16419 , Korea
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29
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Beiderbeck B, Myoga MH, Müller NIC, Callan AR, Friauf E, Grothe B, Pecka M. Precisely timed inhibition facilitates action potential firing for spatial coding in the auditory brainstem. Nat Commun 2018; 9:1771. [PMID: 29720589 PMCID: PMC5932051 DOI: 10.1038/s41467-018-04210-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 04/10/2018] [Indexed: 01/06/2023] Open
Abstract
The integration of excitatory and inhibitory synaptic inputs is fundamental to neuronal processing. In the mammalian auditory brainstem, neurons compare excitatory and inhibitory inputs from the ipsilateral and contralateral ear, respectively, for sound localization. However, the temporal precision and functional roles of inhibition in this integration process are unclear. Here, we demonstrate by in vivo recordings from the lateral superior olive (LSO) that inhibition controls spiking with microsecond precision throughout high frequency click trains. Depending on the relative timing of excitation and inhibition, neuronal spike probability is either suppressed or-unexpectedly-facilitated. In vitro conductance-clamp LSO recordings establish that a reduction in the voltage threshold for spike initiation due to a prior hyperpolarization results in post-inhibitory facilitation of otherwise sub-threshold synaptic events. Thus, microsecond-precise differences in the arrival of inhibition relative to excitation can facilitate spiking in the LSO, thereby promoting spatial sensitivity during the processing of faint sounds.
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Affiliation(s)
- Barbara Beiderbeck
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany
| | - Michael H Myoga
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany.,Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried, 82152, Germany
| | - Nicolas I C Müller
- Department of Biology, Animal Physiology Group, University of Kaiserslautern, Kaiserslautern, D-67653, Germany
| | - Alexander R Callan
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany
| | - Eckhard Friauf
- Department of Biology, Animal Physiology Group, University of Kaiserslautern, Kaiserslautern, D-67653, Germany
| | - Benedikt Grothe
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany. .,Max Planck Institute of Neurobiology, Am Klopferspitz 18, Martinsried, 82152, Germany.
| | - Michael Pecka
- Department Biology II, Division of Neurobiology, Ludwig-Maximilians-Universitaet Munich, Planegg-Martinsried, D-82152, Germany.
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30
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Kondiles BR, Horner PJ. Myelin plasticity, neural activity, and traumatic neural injury. Dev Neurobiol 2017; 78:108-122. [PMID: 28925069 DOI: 10.1002/dneu.22540] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/01/2017] [Accepted: 09/14/2017] [Indexed: 12/12/2022]
Abstract
The possibility that adult organisms exhibit myelin plasticity has recently become a topic of great interest. Many researchers are exploring the role of myelin growth and adaptation in daily functions such as memory and motor learning. Here we consider evidence for three different potential categories of myelin plasticity: the myelination of previously bare axons, remodeling of existing sheaths, and the removal of a sheath with replacement by a new internode. We also review evidence that points to the importance of neural activity as a mechanism by which oligodendrocyte precursor cells (OPCs) are cued to differentiate into myelinating oligodendrocytes, which may potentially be an important component of myelin plasticity. Finally, we discuss demyelination in the context of traumatic neural injury and present an argument for altering neural activity as a potential therapeutic target for remyelination following injury. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 108-122, 2018.
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Affiliation(s)
- Bethany R Kondiles
- Center for Neuroregeneration, Houston Methodist Research Institute, 6670 Bertner Avenue, MSR10-112, Houston, Texas.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Philip J Horner
- Center for Neuroregeneration, Houston Methodist Research Institute, 6670 Bertner Avenue, MSR10-112, Houston, Texas
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31
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Long P, Wan G, Roberts MT, Corfas G. Myelin development, plasticity, and pathology in the auditory system. Dev Neurobiol 2017; 78:80-92. [PMID: 28925106 DOI: 10.1002/dneu.22538] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/23/2017] [Accepted: 09/14/2017] [Indexed: 11/11/2022]
Abstract
Myelin allows for the rapid and precise timing of action potential propagation along neuronal circuits and is essential for healthy auditory system function. In this article, we discuss what is currently known about myelin in the auditory system with a focus on the timing of myelination during auditory system development, the role of myelin in supporting peripheral and central auditory circuit function, and how various myelin pathologies compromise auditory information processing. Additionally, in keeping with the increasing recognition that myelin is dynamic and is influenced by experience throughout life, we review the growing evidence that auditory sensory deprivation alters myelin along specific segments of the brain's auditory circuit. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 80-92, 2018.
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Affiliation(s)
- Patrick Long
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
| | - Guoqiang Wan
- MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, Jiangsu Province, China
| | - Michael T Roberts
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
| | - Gabriel Corfas
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
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32
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Kopp-Scheinpflug C. Your genes decide what you are listening to. Channels (Austin) 2017; 11:355-356. [PMID: 28662361 PMCID: PMC5626367 DOI: 10.1080/19336950.2017.1348870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Conny Kopp-Scheinpflug
- a Division of Neurobiology, Department Biology II , Ludwig-Maximilians-University Munich , Planegg-Martinsried , Germany
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33
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Oertel D, Cao XJ, Ison JR, Allen PD. Cellular Computations Underlying Detection of Gaps in Sounds and Lateralizing Sound Sources. Trends Neurosci 2017; 40:613-624. [PMID: 28867348 DOI: 10.1016/j.tins.2017.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/02/2017] [Accepted: 08/07/2017] [Indexed: 11/29/2022]
Abstract
In mammals, acoustic information arises in the cochlea and is transmitted to the ventral cochlear nuclei (VCN). Three groups of VCN neurons extract different features from the firing of auditory nerve fibers and convey that information along separate pathways through the brainstem. Two of these pathways process temporal information: octopus cells detect coincident firing among auditory nerve fibers and transmit signals along monaural pathways, and bushy cells sharpen the encoding of fine structure and feed binaural pathways. The ability of these cells to signal with temporal precision depends on a low-voltage-activated K+ conductance (gKL) and a hyperpolarization-activated conductance (gh). This 'tale of two conductances' traces gap detection and sound lateralization to their cellular and biophysical origins.
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Affiliation(s)
- Donata Oertel
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705 USA.
| | - Xiao-Jie Cao
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53705 USA
| | - James R Ison
- Department of Brain and Cognitive Sciences, Meliora Hall, University of Rochester, Rochester, NY 14627, USA; Department of Neuroscience, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Paul D Allen
- Department of Otolaryngology, University of Rochester Medical Center, Rochester, NY 14642, USA
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34
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Sound-Evoked Activity Influences Myelination of Brainstem Axons in the Trapezoid Body. J Neurosci 2017; 37:8239-8255. [PMID: 28760859 PMCID: PMC5566870 DOI: 10.1523/jneurosci.3728-16.2017] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 05/31/2017] [Accepted: 06/25/2017] [Indexed: 11/21/2022] Open
Abstract
Plasticity of myelination represents a mechanism to tune the flow of information by balancing functional requirements with metabolic and spatial constraints. The auditory system is heavily myelinated and operates at the upper limits of action potential generation frequency and speed observed in the mammalian CNS. This study aimed to characterize the development of myelin within the trapezoid body, a central auditory fiber tract, and determine the influence sensory experience has on this process in mice of both sexes. We find that in vitro conduction speed doubles following hearing onset and the ability to support high-frequency firing increases concurrently. Also in this time, the diameter of trapezoid body axons and the thickness of myelin double, reaching mature-like thickness between 25 and 35 d of age. Earplugs were used to induce ∼50 dB elevation in auditory thresholds. If introduced at hearing onset, trapezoid body fibers developed thinner axons and myelin than age-matched controls. If plugged during adulthood, the thickest trapezoid body fibers also showed a decrease in myelin. These data demonstrate the need for sensory activity in both development and maintenance of myelin and have important implications in the study of myelin plasticity and how this could relate to sensorineural hearing loss following peripheral impairment.SIGNIFICANCE STATEMENT The auditory system has many mechanisms to maximize the dynamic range of its afferent fibers, which operate at the physiological limit of action potential generation, precision, and speed. In this study we demonstrate for the first time that changes in peripheral activity modifies the thickness of myelin in sensory neurons, not only in development but also in mature animals. The current study suggests that changes in CNS myelination occur as a downstream mechanism following peripheral deficit. Given the required submillisecond temporal precision for binaural auditory processing, reduced myelination might augment sensorineural hearing impairment.
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