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External Education Websites on Hearing

Journey into the World of Hearing

by RĂ©my Pujol et al., INSERM and University of Montpellier

This is an excellent educational website, with a section for Students and Professionals at  www.cochlea.eu/en and a section for the public at www.cochlea.org/en.

 


ARO 2020 Photo Contest

Below you will find stunning images from the research labs of our members, submitted in response to an ARO Art Contest held in January 2020.  These images can be seen scattered throughout our web pages.  Please make sure that you do not use these images without crediting the source.  Thank you, and enjoy!

First Place

Credit:  Patrick Lam, Ella Trang, Niki Gunewardene, and Andrew Wise of Bionics Institute

Description: 3-day culture of primary spiral ganglion cells isolated from 5D neonatal Sprague Dawley rats.This image shows a common phenomenon of spiral ganglion neuron processes being surrounded by glial cells that could play an important role in the nerve survival and signalling.Cells were visualised via immunocytochemistry. Labelled in green are two spiral ganglion neurons using Tuj1 as the primary antibody binding marker; in red are the glial cells using S100 beta as the primary antibody binding marker; all cell nuclei were stained with DAPI in blue.


Second Place- Tied

Credit: David Bächinger, Andreas H. Eckhard

Description: This image shows a quadruple immunostaining a of a whole-mount specimen of the adult murine endolymphatic sac (6 weeks old female C57BL/6J). Lymphatic vessels were stained with an anti-LYVE1 antibody (yellow). Concanavalin A (green) was used to mark blood vessels. The endolymphatic sac is outlined by epithelial staining using a pan-cytokeratin antibody (red). Cell nuclei are marked with DAPI (blue). Note that lymphatic (yellow) and blood vessels (red) form a “star-like” hub in the endolymphatic sac region


Second Place- Tied

Credit: Leonardo R. Andrade of Salk Institute for Biological Studies

Description: SEM image of bullfrog otoconia.


 

Honorable Mentions – 18 photos in no specific order.


Credit: David Bächinger, Andreas H. Eckhard

Description: This image shows an overview of an immunostained section of the adult murine endolymphatic sac (6 weeks old female C57BL/6J).The endolymphatic sacepithelium is outlined using acytokeratin 7 antibody(red) and a calcium sensing receptor (CaSR) antibody(green).Cell nuclei are marked with DAPI (blue).Note that CaSR staining is found exclusively in a subset of cells, which were shown the mitochondria-rich cells of the endolymphatic sac (Bächinger Det al.,Cell Tissue Res.2019). An excerpt of this image appeared on the cover page of the journal “Cell and Tissue Research” (Volume 378, November 2019


Credit: Image is submitted on behalf of freelance Malaysian born artist, Mr Jeganathan Ramachandran by Deborah Hall, Professor of Hearing Sciences, University of Nottingham Malaysia

Description: Artist’s impression of auditory processing in human auditory cortex as captured in two-dimensional form using functional Magnetic Resonance Imaging. Ink drawing on paper, 2018


Credit: Image is submitted on behalf of freelance Malaysian born artist, Mr Jeganathan Ramachandran by Deborah Hall, Professor of Hearing Sciences, University of Nottingham Malaysia

Description: Artist’s impression of the transfer of acoustic energy into neural signals in the human inner ear. Ink drawing on paper, 2018


Credit: Hainan Lang MD, PhD; Medical University of South Carolina; Department of Pathology and Laboratory Medici

Description: A section of the auditory nerve in a young adult CBA/CaJ mouse showing how glial cell associated myelin (blue; CNPase) ensheathed a majority of spiral ganglion neurons(red;Tuj1)


Credit: Hainan Lang,MD, PhD; Medical University of South Carolina; Department of Pathology and Laboratory Medici

Description:  N/A


Credit: Liana Sargsyan and Hongzhe Li, PhD at VA Loma Linda Healthcare System

Description: The mid turn of the cochlea of a 7-week-old C57BL/6 mouse, after a single dose of systemic gentamicin treatment followed by furosemide injection, with immunofluorescent labeling. Antibodies: mouse(IgG1) anti-CtBP2 and goat anti-mouse (IgG1)-AF 568 were used to identify nuclei and ribbon synapses(red). Phalloidin 488 was used to identify outer hair cells (green) in the basal turn of the cochlea.


Credit: Liana Sargsyan and Hongzhe Li, PhD at VA Loma Linda Healthcare System

Description: The basal turn of the cochlea of a 6-week-old mouse in C57BL/6 background, with immunofluorescent labeling. Antibodies: mouse (IgG1) anti-CtBP2 and goat anti-mouse (IgG1)-AF 568 were used to identify nuclei and ribbon synapses (red).Phalloidin 488 was used to identify outer hair cells (green), in the basal turn of the cochlea.


Credit: Liana Sargsyan and Hongzhe Li, PhD at VA Loma Linda Healthcare System

Description: The mid turn of the cochlea of a 6-week-old mouse lacking Duffy antigen receptor for chemokines, with immunofluorescent labeling. Antibodies: mouse (IgG1)anti-CtBP2 and goat anti-mouse (IgG1)-AF 568 were used to identify nuclei and ribbon synapses (red). Phalloidin 488 was used to identify outer hair cells (green), in the mid turn of the cochlea


Credit: Liana Sargsyan and Hongzhe Li, PhD at VA Loma Linda Healthcare System

Description: The mid turn of the cochlea of a 7-week-old C57BL/6 mouse, after a single dose of gentamicin injection,with immunofluorescent labeling. Antibodies: mouse (IgG1) anti-CtBP2 and goat anti-mouse (IgG1)-AF568 were used to identify nuclei and ribbon synapses (red). Anti-neurofilament and AF 488 goat anti-rabbit IgG (H+L) used to identify auditory nerve fibers (green)


Credit: Liana Sargsyan and Hongzhe Li, PhD at VA Loma Linda Healthcare System

Description: The apex of the cochlea of a 6-week-old C57BL/6 mouse, after intratympanic lipopolysaccharide injection, with immunofluorescent labeling. Antibodies: rabbit mAb to IBA1 and anti-rabbit IgG (H+L)were used to identify immune (Iba1+) cells (magenta), and Phalloidin 647 to identify outer hair cells(blue


Credit: Mark Rutherford

Description: Midcochlear organ of Corti (45 kHz region) from ap34 C57BL/6J male mouse. Antibodies label the inner and outer hair cells (blue, Myosin7a), spiral ganglion neurons and medial olivocochlear neurons (red,NaKATPase), and voltage-gated Na+channels (green,NaV1)


Credit: Patrick Lam, Ella Trang, Niki Gunewardene, and Andrew Wise of Bionics Institute

Description: A 3-day culture of primary spiral ganglion cells isolated from 5D neonatal Sprague Dawley rats.This image shows a common phenomenon of spiral ganglion neuron cell bodies being surrounded by glial cells that are likely to share a reciprocal relationship with the seneurons. Cells were visualized via immunocytochemistry. Labelled in green are two spiral ganglion neurons using Tuj1 as the primary antibody binding marker; in red are the glial cells using S100 beta as the primary antibody binding marker; all cell nuclei were stained with DAPI in blue.


Credit: Randy J. Kulesza, Jr. and Yusra Mansour

Description: 3D reconstructions of the nuclei of the Superior Olivary Complex of a neurotypical child (left;8-year-old female) compared to that of a child with Autism Spectrum Disorder (right;8-year-old male).The 3D models were constructed in Amira from Geimsa-stained sections.There is a significant decrease in overall nuclear volume and highly irregular contours of each of the SOC nuclei, in the ASD subject compared to the NT subject, with a preferential effect on theMSO. Key to colors: Medial Superior Olive = red, Lateral Superior Olive = blue, Superior Paraolivary Nucleus = yellow, Medial Nucleus of the Trapezoid Body = green, Ventral Nucleus of the Trapezoid Body = magenta, Lateral Nucleus of the Trapezoid Body = orange.


Credit: Randy J. Kulesza, Jr. and Yusra Mansour

Description: The figure shows a coronal section through the rat central nucleus of the inferior colliculus. Wisteria floribunda-positive Perineuronal nets (cyan) are seen to surround cell bodies and primary dendrites of select neurons. Neurons and glial cells are labelled with Neurotrace Red (magenta)

 


Credit: Shiran Wolland, Roie Cohen, & Shahar Taiber. School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Tel Aviv University

Description: Confocal image of the organ of Corti from P0 Atoh1-mCherry-Zo1-EGFP mouse. 


Credit: Leonardo R. Andrade of Salk Institute for Biological Studies

Description: SEM image showing a 18 days old mouse Organ of Corti with the lookup table gem


Credit: Leonardo R. Andrade of Salk Institute for Biological Studies

Description: Freeze-fracture deep etch of a guinea pig outer hair cell showing the lateral wallwhere prestin motors for cell motility are localized


Credit: Leonardo R. Andrade of Salk Institute for Biological Studies

Description: SEM of bullfrog basilar papilla with two hair cells at opposite orientation

 

To view past photo contest winners and participants, click HERE.

Hearing loss can significantly disrupt the ability of children to become mainstreamed in educational environments that emphasize spoken language as a primary means of communication. Similarly, adults who lose their hearing after communicating using spoken language have numerous challenges understanding speech and integrating into social situations. These challenges are particularly significant in noisy situations, where multiple sound sources often arrive at the ears from various directions. Intervention with hearing aids and/or cochlear implants (CIs) has proven to be highly successful for restoring some aspects of communication, including speech understanding and language acquisition. However, there is also typically a notable gap in outcomes relative to normal-hearing listeners. Importantly, auditory abilities operate in the context of how hearing integrates with other senses. Notably, the visual system is tightly couples to the auditory system. Vision is known to impact auditory perception and neural mechanisms in vision and audition are tightly coupled, thus, in order to understand how we hear and how CIs affect auditory perception we must consider the integrative effects across these senses.

We start with Rebecca Alexander, a compelling public speaker who has been living with Usher’s Syndrome, a genetic disorder found in tens of thousands of people, causing both deafness and blindness in humans. Ms. Alexander will be introduced by Dr. Jeffrey Holt, who studies gene therapy strategies for hearing restoration. The symposium then highlights the work of scientists working across these areas. Here we integrate psychophysics, clinical research, and biological approaches, aiming to gain a coherent understanding of how we might ultimately improve outcomes in patients. Drs. Susana Martinez-Conde and Stephen Macknik are new to the ARO community, and will discuss neurobiology of the visual system as it relates to visual prostheses. Dr. Jennifer Groh’s work will then discuss multi-sensory processing and how it is that vision helps us hear. Having set the stage for thinking about the role of vision in a multisensory auditory world, we will hear from experts in the area of cochlear implants. Dr. René H Gifford will discuss recent work on electric-acoustic integration in children and adults, and Dr. Sharon Cushing will discuss her work as a clinician on 3-D auditory and vestibular effects. Dr. Matthew Winn will talk about cognitive load and listening effort using pupillometry, and we will end with Dr. Rob Shepherd’s discussion of current work and future possibilities involving biological treatments and neural prostheses. Together, these presentations are designed to provide a broad and interdisciplinary view of the impact of sensory restoration in hearing, vision and balance, and the potential for future approaches for improving the lives of patients.

Kirupa Suthakar, PhD - Dr Kirupa Suthakar is a postdoctoral fellow at NIH/NIDCD, having formerly trained as a postdoctoral fellow at Massachusetts Eye and Ear/Harvard Medical School and doctoral student at Garvan Institute of Medical Research/UNSW Australia.  Kirupa's interest in the mind and particular fascination by how we are able to perceive the world around us led her to pursue a research career in auditory neuroscience.  To date, Kirupa's research has broadly focused on neurons within the auditory efferent circuit, which allow the brain to modulate incoming sound signals at the ear.  Kirupa is active member of the spARO community, serving as the Chair Elect for 2021.

 

 

I began studying the vestibular system during my dissertation research at the UniversitĂ  di Pavia with Professors Ivo Prigioni and GianCarlo Russo. I had two postdoctoral fellowships, first at the University of Rochester with Professor Christopher Holt and then at the University of Illinois at Chicago with Professors Jonathan Art and Jay Goldberg.

My research focuses on characterizing the biophysics of synaptic transmission between hair cells and primary afferents in the vestibular system. For many years an outstanding question in vestibular physiology was how the transduction current in the type I hair cell was sufficient, in the face of large conductances on at rest, to depolarize it to potentials necessary for conventional synaptic transmission with its unique afferent calyx.

In collaboration with Dr. Art, I overcame the technical challenges of simultaneously recording from type I hair cells and their enveloping calyx afferent to investigate this question. I was able to show that with depolarization of either hair cell or afferent, potassium ions accumulating in the cleft depolarize the synaptic partner. Conclusions from these studies are that due to the extended apposition between type I hair cell and its afferent, there are three modes of communication across the synapse. The slowest mode of transmission reflects the dynamic changes in potassium ion concentration in the cleft which follow the integral of the ongoing hair cell transduction current. The intermediate mode of transmission is indirectly a result of this potassium elevation which serves as the mechanism by which the hair cell potential is depolarized to levels necessary for calcium influx and the vesicle fusion typical of glutamatergic quanta. This increase in potassium concentration also depolarizes the afferent to potentials that allow the quantal EPSPs to trigger action potentials. The third and most rapid mode of transmission like the slow mode of transmission is bidirectional, and a current flowing out of either hair cell or afferent into the synaptic cleft will divide between a fraction flowing out into the bath, and a fraction flowing across the cleft into its synaptic partner.

The technical achievement of the dual electrode approach has enabled us to identify new facets of vestibular end organ synaptic physiology that in turn raise new questions and challenges for our field. I look forward with great excitement to the next chapter in my scientific story.

 

Charles C. Della Santina, PhD MD is a Professor of Otolaryngology – Head & Neck Surgery and Biomedical Engineering at the Johns Hopkins University School of Medicine, where he directs the Johns Hopkins Cochlear Implant Center and the Johns Hopkins Vestibular NeuroEngineering Laboratory.

As a practicing neurotologic surgeon, Dr. Della Santina specializes in treatment of middle ear, inner ear and auditory/vestibular nerve disorders. His clinical interests include restoration of hearing via cochlear implantation and management of patients who suffer from vestibular disorders, with a particular focus on helping individuals disabled by chronic postural instability and unsteady vision after bilateral loss of vestibular sensation. His laboratory’s research centers on basic and applied research supporting development of vestibular implants, which are medical devices intended to partially restore inner ear sensation of head movement. In addition to that work, his >90 publications include studies characterizing inner ear physiology and anatomy; describing novel clinical tests of vestibular function; and clarifying the effects of cochlear implantation, vestibular implantation, superior canal dehiscence syndrome and intratympanic gentamicin therapy on the inner ear and central nervous system.  Dr. Della Santina is also the founder and CEO/Chief Scientific Officer of Labyrinth Devices LLC, a company dedicated to bringing novel vestibular testing and implant technology into routine clinical care.

Andrew Griffith received his MD and PhD in Molecular Biophysics and Biochemistry from Yale University in 1992. He completed his general surgery internship and a residency in Otolaryngology-Head and Neck Surgery at the University of Michigan in 1998. He also completed a postdoctoral research fellowship in the Department of Human Genetics as part of his training at the University of Michigan. In 1998, he joined the Division of Intramural Research (DIR) in the National Institute on Deafness and Other Communication Disorders (NIDCD). He served as a senior investigator, the chief of the Molecular Biology and Genetics Section, the chief of the Otolaryngology Branch, and the director of the DIR, as well as the deputy director for Intramural Clinical Research across the NIH Intramural Research Program. His research program identifies and characterizes molecular and cellular mechanisms of normal and disordered hearing and balance in humans and mouse models. Two primary interests of his program have been hearing loss associated with enlargement of the vestibular aqueduct, and the function of TMC genes and proteins. The latter work lead to the discovery that the deafness gene product TMC1 is a component of the hair cell sensory transduction channel. Since July of 2020, he has served as the Senior Associate Dean of Research and a Professor of Otolaryngology and Physiology in the College of Medicine at the University of Tennessee Health Science Center.

Gwenaëlle S. G. Géléoc obtained a PhD in Sensory Neurobiology from the University of Sciences in Montpellier (France) in 1996. She performed part of her PhD training at the University of Sussex, UK where she characterized sensory transduction in vestibular hair cells and a performed a comparative study between vestibular and cochlear hair cells. Gwenaelle continued her training as an electrophysiologist at University College London studying outer hair cell motility and at Harvard Medical School studying modulation of mechanotransduction in vestibular hair cells. As an independent investigator at the University of Virginia, she expanded this work and characterized the developmental acquisition of sensory transduction in mouse vestibular hair cells, the developmental acquisition of voltage-sensitive conductances in vestibular hair cells and the tonotopic gradient in the acquisition of sensory transduction in the mouse cochlea. This work along with quantitative spatio-temporal studies performed on several hair cell mechanotransduction candidates lead her to TMC1 and 2 and long-term collaborations with Andrew Griffith and Jeff Holt. Dr. Géléoc is currently Assistant Professor of Otolaryngology, at Boston Children’s Hospital where she continues to study molecular players involved in the development and function of hair cells of the inner ear and develops new therapies for the treatment of deafness and balance, with a particular focus on Usher syndrome.

Jeff Holt earned a doctorate from the Department of Physiology at the University of Rochester in 1995 for his studies of inward rectifier potassium channels in saccular hair cells.  He went on to a post-doctoral position in the Neurobiology Department at Harvard Medical School and the Howard Hughes Medical Institute, where he characterized sensory transduction and adaptation in hair cells and developed a viral vector system to transfect cultured hair cells.  Dr. Holt’s first faculty position was in the Neuroscience Department at the University of Virginia.  In 2011 the lab moved to Boston Children’s Hospital / Harvard Medical School.  Dr. Holt is currently a Professor in the Departments of Otolaryngology and Neurology in the F.M. Kirby Neurobiology Center.  Dr. Holt and his team have been studying sensory transduction in auditory and vestibular hair cells over the past 20 years, with particular focus on TMC1 and TMC2 over the past 12 years.  This work lead to the discovery that TMC1 forms the hair cell transduction channel.  His work also focuses on development gene therapy strategies for genetic hearing loss.​