1
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Mitchell PW, Carney LH. A computational model of auditory chirp-velocity sensitivity and amplitude-modulation tuning in inferior colliculus neurons. J Comput Neurosci 2024:10.1007/s10827-024-00880-4. [PMID: 39259462 DOI: 10.1007/s10827-024-00880-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 08/14/2024] [Accepted: 08/17/2024] [Indexed: 09/13/2024]
Abstract
We demonstrate a model of chirp-velocity sensitivity in the inferior colliculus (IC) that retains the tuning to amplitude modulation (AM) that was established in earlier models. The mechanism of velocity sensitivity is sequence detection by octopus cells of the posteroventral cochlear nucleus, which have been proposed in physiological studies to respond preferentially to the order of arrival of cross-frequency inputs of different amplitudes. Model architecture is based on coincidence detection of a combination of excitatory and inhibitory inputs. Chirp-sensitivity of the IC output is largely controlled by the strength and timing of the chirp-sensitive octopus-cell inhibitory input. AM tuning is controlled by inhibition and excitation that are tuned to the same frequency. We present several example neurons that demonstrate the feasibility of the model in simulating realistic chirp-sensitivity and AM tuning for a wide range of characteristic frequencies. Additionally, we explore the systematic impact of varying parameters on model responses. The proposed model can be used to assess the contribution of IC chirp-velocity sensitivity to responses to complex sounds, such as speech.
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Affiliation(s)
- Paul W Mitchell
- Department of Biomedical Engineering and Neuroscience, University of Rochester, Rochester, NY, USA
| | - Laurel H Carney
- Department of Biomedical Engineering and Neuroscience, University of Rochester, Rochester, NY, USA.
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2
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Joris PX, Verschooten E. Midbrain sensitivity to auditory motion studied with dichotic sweeps of broadband noise. Hear Res 2024; 450:109066. [PMID: 38889563 DOI: 10.1016/j.heares.2024.109066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/18/2024] [Accepted: 06/02/2024] [Indexed: 06/20/2024]
Abstract
Many neurons in the central nucleus of the inferior colliculus (IC) show sensitivity to interaural time differences (ITDs), which is thought to be relayed from the brainstem. However, studies with interaural phase modulation of pure tones showed that IC neurons have a sensitivity to changes in ITD that is not present at the level of the brainstem. This sensitivity has been interpreted as a form of sensitivity to motion. A new type of stimulus is used here to study the sensitivity of IC neurons to dynamic changes in ITD, in which broad- or narrowband stimuli are swept through a range of ITDs with arbitrary start-ITD, end-ITD, speed, and direction. Extracellular recordings were obtained under barbiturate anesthesia in the cat. We applied the same analyses as previously introduced for the study of responses to tones. We find effects of motion which are similar to those described in response to interaural phase modulation of tones. The size of the effects strongly depended on the motion parameters but was overall smaller than reported for tones. We found that the effects of motion could largely be explained by the temporal response pattern of the neuron such as adaptation and build-up. Our data add to previous evidence questioning true coding of motion at the level of the IC.
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Affiliation(s)
- Philip X Joris
- Lab. of Auditory Neurophysiology, KU Leuven, Herestraat 49 B-3000 Leuven, Belgium; Dept. of Neuroscience, UW-Madison, 111 Highland Avenue, Madison, WI 53705-2275, USA.
| | - Eric Verschooten
- Lab. of Auditory Neurophysiology, KU Leuven, Herestraat 49 B-3000 Leuven, Belgium
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3
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Vaziri PA, McDougle SD, Clark DA. Humans use local spectrotemporal correlations to detect rising and falling pitch. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.03.606481. [PMID: 39131316 PMCID: PMC11312537 DOI: 10.1101/2024.08.03.606481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
To discern speech or appreciate music, the human auditory system detects how pitch increases or decreases over time. However, the algorithms used to detect changes in pitch, or pitch motion, are incompletely understood. Here, using psychophysics, computational modeling, functional neuroimaging, and analysis of recorded speech, we ask if humans detect pitch motion using computations analogous to those used by the visual system. We adapted stimuli from studies of vision to create novel auditory correlated noise stimuli that elicited robust pitch motion percepts. Crucially, these stimuli possess no persistent features across frequency or time, but do possess positive or negative local spectrotemporal correlations in intensity. In psychophysical experiments, we found clear evidence that humans judge pitch direction based on both positive and negative spectrotemporal correlations. The observed sensitivity to negative correlations is a direct analogue of illusory "reverse-phi" motion in vision, and thus constitutes a new auditory illusion. Our behavioral results and computational modeling led us to hypothesize that human auditory processing employs pitch direction opponency. fMRI measurements in auditory cortex supported this hypothesis. To link our psychophysical findings to real-world pitch perception, we analyzed recordings of English and Mandarin speech and discovered that pitch direction was robustly signaled by the same positive and negative spectrotemporal correlations used in our psychophysical tests, suggesting that sensitivity to both positive and negative correlations confers ecological benefits. Overall, this work reveals that motion detection algorithms sensitive to local correlations are deployed by the central nervous system across disparate modalities (vision and audition) and dimensions (space and frequency).
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Affiliation(s)
| | - Samuel D McDougle
- Dept of Psychology, Yale University, New Haven, CT 06511
- Wu Tsai Institute, Yale University, New Haven, CT 06511
| | - Damon A Clark
- Wu Tsai Institute, Yale University, New Haven, CT 06511
- Dept of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511
- Dept of Physics, Yale University, New Haven, CT 06511
- Dept of Neuroscience, Yale University, New Haven, CT 06511
- Quantitative Biology Institute, Yale University, New Haven, CT 06511
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4
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Pyott SJ, Pavlinkova G, Yamoah EN, Fritzsch B. Harmony in the Molecular Orchestra of Hearing: Developmental Mechanisms from the Ear to the Brain. Annu Rev Neurosci 2024; 47:1-20. [PMID: 38360566 DOI: 10.1146/annurev-neuro-081423-093942] [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] [Indexed: 02/17/2024]
Abstract
Auditory processing in mammals begins in the peripheral inner ear and extends to the auditory cortex. Sound is transduced from mechanical stimuli into electrochemical signals of hair cells, which relay auditory information via the primary auditory neurons to cochlear nuclei. Information is subsequently processed in the superior olivary complex, lateral lemniscus, and inferior colliculus and projects to the auditory cortex via the medial geniculate body in the thalamus. Recent advances have provided valuable insights into the development and functioning of auditory structures, complementing our understanding of the physiological mechanisms underlying auditory processing. This comprehensive review explores the genetic mechanisms required for auditory system development from the peripheral cochlea to the auditory cortex. We highlight transcription factors and other genes with key recurring and interacting roles in guiding auditory system development and organization. Understanding these gene regulatory networks holds promise for developing novel therapeutic strategies for hearing disorders, benefiting millions globally.
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Affiliation(s)
- Sonja J Pyott
- Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Groningen, Graduate School of Medical Sciences, and Research School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czechia
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Bernd Fritzsch
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA;
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5
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Šodan A, Meunier S, Péan V, Lavieille JP, Roman S, Macherey O. Asymmetry in the Perception of Electrical Chirps Presented to Cochlear Implant Listeners. J Assoc Res Otolaryngol 2024:10.1007/s10162-024-00952-3. [PMID: 39090303 DOI: 10.1007/s10162-024-00952-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 05/11/2024] [Indexed: 08/04/2024] Open
Abstract
INTRODUCTION Although a broadband acoustic click is physically the shortest duration sound we can hear, its peripheral neural representation is not as short because of cochlear filtering. The traveling wave imposes frequency-dependent delays to the sound waveform so that in response to a click, apical nerve fibers, coding for low frequencies, are excited several milliseconds after basal fibers, coding for high frequencies. Nevertheless, a click sounds like a click and these across-fiber delays are not perceived. This suggests that they may be compensated by the central auditory system, rendering our perception consistent with the external world. This explanation is difficult to evaluate in normal-hearing listeners because the contributions of peripheral and central auditory processing cannot easily be disentangled. Here, we test this hypothesis in cochlear implant listeners for whom cochlear mechanics is bypassed. METHOD Eight cochlear implant users ranked in perceived duration 12 electrical chirps of various physical durations and spanning the cochlea in the apex-to-base or base-to-apex direction (Exp. 1). Late-latency cortical potentials were also recorded in response to a subset of these chirps (Exp. 2). RESULTS We show that an electrical chirp spanning the cochlea from base-to-apex is perceived as shorter than the same chirp spanning the cochlea in the opposite direction despite having the same physical duration. Cortical potentials also provide neural correlates of this asymmetry in perception. CONCLUSION These results demonstrate that the central auditory system processes frequency sweeps differently depending on the direction of the frequency change and that this processing difference is not simply the result of peripheral filtering.
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Affiliation(s)
- Ana Šodan
- Aix Marseille Univ, CNRS, Centrale Marseille, LMA UMR 7031, 13013, Marseille, France.
| | - Sabine Meunier
- Aix Marseille Univ, CNRS, Centrale Marseille, LMA UMR 7031, 13013, Marseille, France
| | | | - Jean-Pierre Lavieille
- Department of ORL, Laboratory of Applied Biomechanics, LDV unit, 13002, Marseille, France
- University Hospital Nord, 13015, Marseille, France
| | - Stéphane Roman
- Institut de Neurosciences des systèmes, Inserm UMR1106, Aix-Marseille Univ., 13005, Marseille, France
- Dept. of Pediatric Otolaryngology and Neck Surgery, Aix-Marseille Univ., 13005, Marseille, France
| | - Olivier Macherey
- Aix Marseille Univ, CNRS, Centrale Marseille, LMA UMR 7031, 13013, Marseille, France
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6
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Mitchell PW, Carney LH. A Computational Model of Auditory Chirp-Velocity Sensitivity and Amplitude-Modulation Tuning in Inferior Colliculus Neurons. RESEARCH SQUARE 2024:rs.3.rs-4450943. [PMID: 38883707 PMCID: PMC11177976 DOI: 10.21203/rs.3.rs-4450943/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
We demonstrate a model of chirp-velocity sensitivity in the inferior colliculus (IC) that retains the tuning to amplitude modulation (AM) that was established in earlier models. The mechanism of velocity sensitivity is sequence detection by octopus cells of the posteroventral cochlear nucleus, which have been proposed in physiological studies to respond preferentially to the order of arrival of cross-frequency inputs of different amplitudes. Model architecture is based on coincidence detection of a combination of excitatory and inhibitory inputs. Chirp-sensitivity of the IC output is largely controlled by the strength and timing of the chirp-sensitive octopus-cell inhibitory input. AM tuning is controlled by inhibition and excitation that are tuned to the same frequency. We present several example neurons that demonstrate the feasibility of the model in simulating realistic chirp-sensitivity and AM tuning for a wide range of characteristic frequencies. Additionally, we explore the systematic impact of varying parameters on model responses. The proposed model can be used to assess the contribution of IC chirp-velocity sensitivity to responses to complex sounds, such as speech.
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Affiliation(s)
- Paul W. Mitchell
- Department of Biomedical Engineering, University of Rochester, 601 Elmwood Ave, Rochester, NY, 14642, USA
| | - Laurel H. Carney
- Department of Biomedical Engineering, University of Rochester, 601 Elmwood Ave, Rochester, NY, 14642, USA
- Department of Neuroscience, University of Rochester, 601 Elmwood Ave, Rochester, NY, 14642, USA
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7
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Tschumak A, Feldhoff F, Klefenz F. The switching and learning behavior of an octopus cell implemented on FPGA. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2024; 21:5762-5781. [PMID: 38872557 DOI: 10.3934/mbe.2024254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
A dendrocentric backpropagation spike timing-dependent plasticity learning rule has been derived based on temporal logic for a single octopus neuron. It receives parallel spike trains and collectively adjusts its synaptic weights in the range [0, 1] during training. After the training phase, it spikes in reaction to event signaling input patterns in sensory streams. The learning and switching behavior of the octopus cell has been implemented in field-programmable gate array (FPGA) hardware. The application in an FPGA is described and the proof of concept for its application in hardware that was obtained by feeding it with spike cochleagrams is given; also, it is verified by performing a comparison with the pre-computed standard software simulation results.
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Affiliation(s)
- Alexej Tschumak
- Audio Communication Group, Technische Universität Berlin, Berlin, Germany
| | - Frank Feldhoff
- Advanced Electromagnetics Group, Technische Universität Ilmenau, Ilmenau, Germany
| | - Frank Klefenz
- Fraunhofer Institute for Digital Media Technology, Ilmenau, Germany
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8
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Kreeger LJ, Honnuraiah S, Maeker S, Shea S, Fishell G, Goodrich LV. An Anatomical and Physiological Basis for Coincidence Detection Across Time Scales in the Auditory System. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582808. [PMID: 38464181 PMCID: PMC10925315 DOI: 10.1101/2024.02.29.582808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Coincidence detection is a common neural computation that identifies co-occurring stimuli by integration of inputs. In the auditory system, octopus cells act as coincidence detectors for complex sounds that include both synchronous and sequenced combinations of frequencies. Octopus cells must detect coincidence on both the millisecond and submillisecond time scale, unlike the average neuron, which integrates inputs over time on the order of tens of milliseconds. Here, we show that octopus cell computations in the cell body are shaped by inhibition in the dendrites, which adjusts the strength and timing of incoming signals to achieve submillisecond acuity. This mechanism is crucial for the fundamental process of integrating the synchronized frequencies of natural auditory signals over time.
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Affiliation(s)
- Lauren J Kreeger
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
| | - Suraj Honnuraiah
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sydney Maeker
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
| | - Siobhan Shea
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
| | - Gord Fishell
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Lisa V Goodrich
- Harvard Medical School, Department of Neurobiology, Boston, MA 02115, USA
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9
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Drotos AC, Roberts MT. Identifying neuron types and circuit mechanisms in the auditory midbrain. Hear Res 2024; 442:108938. [PMID: 38141518 PMCID: PMC11000261 DOI: 10.1016/j.heares.2023.108938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/27/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
The inferior colliculus (IC) is a critical computational hub in the central auditory pathway. From its position in the midbrain, the IC receives nearly all the ascending output from the lower auditory brainstem and provides the main source of auditory information to the thalamocortical system. In addition to being a crossroads for auditory circuits, the IC is rich with local circuits and contains more than five times as many neurons as the nuclei of the lower auditory brainstem combined. These results hint at the enormous computational power of the IC, and indeed, systems-level studies have identified numerous important transformations in sound coding that occur in the IC. However, despite decades of effort, the cellular mechanisms underlying IC computations and how these computations change following hearing loss have remained largely impenetrable. In this review, we argue that this challenge persists due to the surprisingly difficult problem of identifying the neuron types and circuit motifs that comprise the IC. After summarizing the extensive evidence pointing to a diversity of neuron types in the IC, we highlight the successes of recent efforts to parse this complexity using molecular markers to define neuron types. We conclude by arguing that the discovery of molecularly identifiable neuron types ushers in a new era for IC research marked by molecularly targeted recordings and manipulations. We propose that the ability to reproducibly investigate IC circuits at the neuronal level will lead to rapid advances in understanding the fundamental mechanisms driving IC computations and how these mechanisms shift following hearing loss.
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Affiliation(s)
- Audrey C Drotos
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109, United States
| | - Michael T Roberts
- Kresge Hearing Research Institute, Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, MI 48109, United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, United States.
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10
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Li YH, Joris PX. Case reopened: A temporal basis for harmonic pitch templates in the early auditory system?a). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3986-4003. [PMID: 38149819 DOI: 10.1121/10.0023969] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 12/04/2023] [Indexed: 12/28/2023]
Abstract
A fundamental assumption of rate-place models of pitch is the existence of harmonic templates in the central nervous system (CNS). Shamma and Klein [(2000). J. Acoust. Soc. Am. 107, 2631-2644] hypothesized that these templates have a temporal basis. Coincidences in the temporal fine-structure of neural spike trains, even in response to nonharmonic, stochastic stimuli, would be sufficient for the development of harmonic templates. The physiological plausibility of this hypothesis is tested. Responses to pure tones, low-pass noise, and broadband noise from auditory nerve fibers and brainstem "high-sync" neurons are studied. Responses to tones simulate the output of fibers with infinitely sharp filters: for these responses, harmonic structure in a coincidence matrix comparing pairs of spike trains is indeed found. However, harmonic template structure is not observed in coincidences across responses to broadband noise, which are obtained from nerve fibers or neurons with enhanced synchronization. Using a computer model based on that of Shamma and Klein, it is shown that harmonic templates only emerge when consecutive processing steps (cochlear filtering, lateral inhibition, and temporal enhancement) are implemented in extreme, physiologically implausible form. It is concluded that current physiological knowledge does not support the hypothesis of Shamma and Klein (2000).
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Affiliation(s)
- Yi-Hsuan Li
- Laboratory of Auditory Neurophysiology, Medical School, Campus Gasthuisberg, University of Leuven, B-3000 Leuven, Belgium
| | - Philip X Joris
- Laboratory of Auditory Neurophysiology, Medical School, Campus Gasthuisberg, University of Leuven, B-3000 Leuven, Belgium
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11
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Mitchell PW, Henry KS, Carney LH. Sensitivity to direction and velocity of fast frequency chirps in the inferior colliculus of awake rabbit. Hear Res 2023; 440:108915. [PMID: 37992517 PMCID: PMC10847965 DOI: 10.1016/j.heares.2023.108915] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 10/20/2023] [Accepted: 11/14/2023] [Indexed: 11/24/2023]
Abstract
Neurons in the mammalian inferior colliculus (IC) are sensitive to the velocity (speed and direction) of fast frequency chirps contained in Schroeder-phase harmonic complexes (SCHR). However, IC neurons are also sensitive to stimulus periodicity, a prominent feature of SCHR stimuli. Here, to disentangle velocity sensitivity from periodicity tuning, we introduced a novel stimulus consisting of aperiodic random chirps. Extracellular, single-unit recordings were made in the IC of Dutch-belted rabbits in response to both SCHR and aperiodic chirps. Rate-velocity functions were constructed from aperiodic-chirp responses and compared to SCHR rate profiles, revealing interactions between stimulus periodicity and neural velocity sensitivity. A generalized linear model analysis demonstrated that periodicity tuning influences SCHR response rates more strongly than velocity sensitivity. Principal component analysis of rate-velocity functions revealed that neurons were more often sensitive to the direction of lower-velocity chirps and were less often sensitive to the direction of higher-velocity chirps. Overall, these results demonstrate that sensitivity to chirp velocity is common in the IC. Harmonic sounds with complex phase spectra, such as speech and music, contain chirps, and velocity sensitivity would shape IC responses to these sounds.
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Affiliation(s)
- Paul W Mitchell
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | - Kenneth S Henry
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA; Departments of Neuroscience, University of Rochester, Rochester, NY, USA; Departments of Otolaryngology, University of Rochester, Rochester, NY, USA
| | - Laurel H Carney
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA; Departments of Neuroscience, University of Rochester, Rochester, NY, USA.
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12
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Jing J, Hu M, Ngodup T, Ma Q, Lau SNN, Ljungberg C, McGinley MJ, Trussell LO, Jiang X. Comprehensive analysis of cellular specializations that initiate parallel auditory processing pathways in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.15.539065. [PMID: 37293040 PMCID: PMC10245571 DOI: 10.1101/2023.05.15.539065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The cochlear nuclear complex (CN) is the starting point for all central auditory processing and comprises a suite of neuronal cell types that are highly specialized for neural coding of acoustic signals. To examine how their striking functional specializations are determined at the molecular level, we performed single-nucleus RNA sequencing of the mouse CN to molecularly define all constituent cell types and related them to morphologically- and electrophysiologically-defined neurons using Patch-seq. We reveal an expanded set of molecular cell types encompassing all previously described major types and discover new subtypes both in terms of topographic and cell-physiologic properties. Our results define a complete cell-type taxonomy in CN that reconciles anatomical position, morphological, physiological, and molecular criteria. This high-resolution account of cellular heterogeneity and specializations from the molecular to the circuit level illustrates molecular underpinnings of functional specializations and enables genetic dissection of auditory processing and hearing disorders with unprecedented specificity.
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Affiliation(s)
- Junzhan Jing
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Ming Hu
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Tenzin Ngodup
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Qianqian Ma
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Shu-Ning Natalie Lau
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Cecilia Ljungberg
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Matthew J. McGinley
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Laurence O. Trussell
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, OR, USA
| | - Xiaolong Jiang
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
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13
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Henry KS, Wang Y, Abrams KS, Carney LH. Mechanisms of masking by Schroeder-phase harmonic tone complexes in the budgerigar (Melopsittacus undulatus). Hear Res 2023; 435:108812. [PMID: 37269601 PMCID: PMC10330901 DOI: 10.1016/j.heares.2023.108812] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/05/2023] [Accepted: 05/24/2023] [Indexed: 06/05/2023]
Abstract
Schroeder-phase harmonic tone complexes can have a flat temporal envelope and rising or falling instantaneous-frequency sweeps within F0 periods, depending on the phase-scaling parameter C. Human tone-detection thresholds in a concurrent Schroeder masker are 10-15 dB lower for positive C values (rising frequency sweeps) compared to negative (falling sweeps), potentially due to cochlear mechanics, though this hypothesis remains controversial. Birds provide an interesting model for studies of Schroeder masking because many species produce vocalizations containing frequency sweeps. Prior behavioral studies in birds suggest less behavioral threshold difference between maskers with opposite C values than in humans, but focused on low masker F0s and did not explore neural mechanisms. We performed behavioral Schroeder-masking experiments in budgerigars (Melopsittacus undulatus) using a wide range of masker F0 and C values. Signal frequency was 2800 Hz. Neural recordings from the midbrain characterized encoding of behavioral stimuli in awake animals. Behavioral thresholds increased with increasing masker F0 and showed minimal difference between opposite C values, consistent with prior budgerigar studies. Midbrain recordings showed prominent temporal and rate-based encoding of Schroeder F0, and in many cases, marked asymmetry in Schroeder responses between C polarities. Neural thresholds for Schroeder-masked tone detection were often based on a response decrement compared to the masker alone, consistent with prominent modulation tuning in midbrain neurons, and were generally similar between opposite C values. The results highlight the likely importance of envelope cues in Schroeder masking and show that differences in supra-threshold Schroeder responses do not necessarily result in neural threshold differences.
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Affiliation(s)
- Kenneth S Henry
- Department of Otolaryngology; Department of Biomedical Engineering; Department of Neuroscience, University of Rochester, Rochester, NY 14642, United States.
| | | | - Kristina S Abrams
- Department of Neuroscience, University of Rochester, Rochester, NY 14642, United States
| | - Laurel H Carney
- Department of Biomedical Engineering; Department of Neuroscience, University of Rochester, Rochester, NY 14642, United States.
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14
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Ma Y, Shu WC, Lin L, Cao XJ, Oertel D, Smith PH, Jackson MB. Imaging Voltage Globally and in Isofrequency Lamina in Slices of Mouse Ventral Cochlear Nucleus. eNeuro 2023; 10:ENEURO.0465-22.2023. [PMID: 36792362 PMCID: PMC9997695 DOI: 10.1523/eneuro.0465-22.2023] [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: 11/15/2022] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
The cochlear nuclei (CNs) receive sensory information from the ear and perform fundamental computations before relaying this information to higher processing centers. These computations are performed by distinct types of neurons interconnected in circuits dedicated to the specialized roles of the auditory system. In the present study, we explored the use of voltage imaging to investigate CN circuitry. We tested two approaches based on fundamentally different voltage sensing technologies. Using a voltage-sensitive dye we recorded glutamate receptor-independent signals arising predominantly from axons. The mean conduction velocity of these fibers of 0.27 m/s was rapid but in range with other unmyelinated axons. We then used a genetically-encoded hybrid voltage sensor (hVOS) to image voltage from a specific population of neurons. Probe expression was controlled using Cre recombinase linked to c-fos activation. This activity-induced gene enabled targeting of neurons that are activated when a mouse hears a pure 15-kHz tone. In CN slices from these animals auditory nerve fiber stimulation elicited a glutamate receptor-dependent depolarization in hVOS probe-labeled neurons. These cells resided within a band corresponding to an isofrequency lamina, and responded with a high degree of synchrony. In contrast to the axonal origin of voltage-sensitive dye signals, hVOS signals represent predominantly postsynaptic responses. The introduction of voltage imaging to the CN creates the opportunity to investigate auditory processing circuitry in populations of neurons targeted on the basis of their genetic identity and their roles in sensory processing.
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Affiliation(s)
- Yihe Ma
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Wen-Chi Shu
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Lin Lin
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Xiao-Jie Cao
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Donata Oertel
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Philip H Smith
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
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