Intrinsic and Synaptic Mechanisms Underlying Sound Localization in the Avian Auditory Brainstem PDF Download

Author: Sean Joseph Slee
Publisher:
ISBN:
Category :
Languages : en
Pages : 206

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Author: Rebecca J. Curry
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The ability to localize sound in space is an important task for communication and survival in complex acoustic environments for both humans and animals. For localizing sound in the horizontal plane, differences in sound information received by each ear generates binaural cues, such as the interaural level difference (ILD). Using whole-cell recordings in brain slices, this work focuses on the basic properties of synaptic inhibition in the avian ILD circuit, as well as the modulation of inhibition in the mammalian ILD circuit, both of which are critical for understanding the range of cellular sound localization coding solutions. In birds, the posterior portion of the dorsal nucleus of the lateral lemniscus (LLDp) encodes the ILD, but little is known about the mechanisms of synaptic inhibition underlying the ILD coding. Here, I provide the first evidence confirming a monosynaptic inhibition driven by direct electrical and chemical stimulation of the contralateral LLDp. Additionally, inhibition to LLDp neurons was largely GABAergic, although there is evidence for a glycinergic component, and the low internal chloride concentration suggests a hyperpolarizing action of inhibition in this circuit. In mammals, the medial nucleus of the trapezoid body (MNTB) provides synaptic inhibition to many auditory brainstem nuclei including the mammalian ILD encoding nucleus, and thus contributes to ILD coding. However, not much is understood of the synaptic inhibition the MNTB itself receives and it remains entirely unknown how this inhibition is regulated. Here, I investigated group I metabotropic glutamate receptor (mGluR I) modulation of the glycinergic and GABAergic inputs to MNTB neurons in both wildtype (WT) mice and a fragile X syndrome (FXS) mouse model, in which the fragile X mental retardation gene 1 is knocked out (Fmr1 KO). Loss of the FMR protein results in exaggerated activity of mGluR I, allowing for comparisons of mGluR I function under normal and disordered conditions. Activation of group I mGluRs by 3,5-DHPG (200 ℗æM) increased sIPSC frequency and amplitude in both WT and Fmr1 KO neurons in a voltage-gated sodium channel dependent fashion for glycinergic transmission, but did not modulate glycinergic eIPSCs. For GABAergic transmission, 3,5-DHPG did not increase sIPSC frequency or amplitude, but did suppress eIPSCs in WT neurons. These findings suggest differential modulation by mGluR I on specific inhibitory neurotransmitters and specific neurotransmitter release modes. Together, the results provide new insight to the role of synaptic inhibition in the computation of sound localization across animal models, establishing a working cellular model for avian ILD coding and laying the foundation for the role of mGluR I modulation in the mammalian MNTB under normal and disease states.

Author: Gordon M. Shepherd
Publisher: Oxford University Press
ISBN: 0190636114
Category : Medical
Languages : en
Pages : 625

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In order to focus on principles, each chapter in this work is brief, organized around 1-3 wiring diagrams of the key circuits, with several pages of text that distil the functional significance of each microcircuit

Author: Laurence O. Trussell
Publisher: Springer
ISBN: 9781441995186
Category : Science
Languages : en
Pages : 234

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Book Description
Synaptic Mechanisms in the Auditory System will provide a basic reference for students, clinicians, and researchers on how synapses in the auditory system function to encode acoustic signals. These mechanisms are the groundwork for all auditory processing, and understanding them requires knowledge of the microphysiology of synapses, cellular biophysics, receptor pharmacology, and an appreciation for what these synapses must do for a living, what unique jobs they carry out.

Author: J. A. Altman
Publisher:
ISBN:
Category : Auditory perception
Languages : en
Pages : 50

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Author: Laurence O. Trussell
Publisher: Springer Science & Business Media
ISBN: 144199517X
Category : Science
Languages : en
Pages : 242

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Book Description
Synaptic Mechanisms in the Auditory System will provide a basic reference for students, clinicians, and researchers on how synapses in the auditory system function to encode acoustic signals. These mechanisms are the groundwork for all auditory processing, and understanding them requires knowledge of the microphysiology of synapses, cellular biophysics, receptor pharmacology, and an appreciation for what these synapses must do for a living, what unique jobs they carry out.

Author: Raymond Romand
Publisher: Academic Press
ISBN: 0124081088
Category : Science
Languages : en
Pages : 563

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Book Description
Development of Auditory and Vestibular Systems fourth edition presents a global and synthetic view of the main aspects of the development of the stato-acoustic system. Unique to this volume is the joint discussion of two sensory systems that, although close at the embryological stage, present divergences during development and later reveal conspicuous functional differences at the adult stage. This work covers the development of auditory receptors up to the central auditory system from several animal models, including humans. Coverage of the vestibular system, spanning amphibians to effects of altered gravity during development in different species, offers examples of the diversity and complexity of life at all levels, from genes through anatomical form and function to, ultimately, behavior. The new edition of Development of Auditory and Vestibular Systems will continue to be an indispensable resource for beginning scientists in this area and experienced researchers alike. - Full-color figures illustrate the development of the stato-acoustic system pathway - Covers a broad range of species, from drosophila to humans, demonstrating the diversity of morphological development despite similarities in molecular processes involved at the cellular level - Discusses a variety of approaches, from genetic-molecular biology to psychophysics, enabling the investigation of ontogenesis and functional development

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 946

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Author: Donata Oertel
Publisher: Springer Science & Business Media
ISBN: 9780387989037
Category : Medical
Languages : en
Pages : 450

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A summary of how the electrical signals used to represent sounds are encoded and interpreted through the integrated roles of various nuclei. This volume builds on the information about the anatomy and physiology of the auditory pathway found in volumes 1 and 2 of the SHAR series. While the first two volumes describe the structure and function of auditory pathways, this one explains how these pathways lead to an animal's ability to localize and interpret sounds.

Author: Ruth Y. Litovsky
Publisher: Springer Nature
ISBN: 3030571009
Category : Medical
Languages : en
Pages : 425

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Book Description
The field of Binaural Hearing involves studies of auditory perception, physiology, and modeling, including normal and abnormal aspects of the system. Binaural processes involved in both sound localization and speech unmasking have gained a broader interest and have received growing attention in the published literature. The field has undergone some significant changes. There is now a much richer understanding of the many aspects that comprising binaural processing, its role in development, and in success and limitations of hearing-aid and cochlear-implant users. The goal of this volume is to provide an up-to-date reference on the developments and novel ideas in the field of binaural hearing. The primary readership for the volume is expected to be academic specialists in the diverse fields that connect with psychoacoustics, neuroscience, engineering, psychology, audiology, and cochlear implants. This volume will serve as an important resource by way of introduction to the field, in particular for graduate students, postdoctoral scholars, the faculty who train them and clinicians.