About the Researcher

Choongheon Lee, PhD, is an Assistant Professor of Research at the University of Rochester. He completed his PhD under Dr. Timothy Jones at the University of Nebraska-Lincoln, where he specialized in recording short-latency VsEPs in mammalian species and developed a strong interest in peripheral vestibular physiology. His research integrates electrophysiological and pharmacological approaches to investigate inner ear function, with a current focus on translating successful animal-model findings into clinical applications for diagnosing vestibular disorders.

About the Research

Translational Research in Vestibular Diagnostics: Direct Assessment of Human Gravity Receptors

Dizziness is a common complaint in primary care, often causing chronic symptoms that affect quality of life. Current vestibular tests primarily assess central relay neurons, overlooking direct activation of peripheral vestibular sensors. This project aims to carefully translate successful animal-model methods to human clinical practice by adapting short-latency linear VsEPs. By optimizing stimulus parameters and refining recording techniques, we will validate short latency VsEPs in young adults. These preliminary efforts will pave the way for a standardized diagnostic tool, offering more accurate diagnoses of dizziness and balance disorders, ultimately improving patient care.

About the Researcher

Federica M. Raciti, PhD, is a postdoctoral researcher in the NeuroTherapeutics Lab within the Otolaryngology Department at the University of Miami, mentored by Dr. Suhrud Rajguru. She earned her Ph.D. in Physiology and Biophysics from the same institution, after completing her Master’s degree in Molecular Biotechnology at Università Statale di Milano under Dr. Michele Mazzanti. Her doctoral research explored molecular mechanisms underlying physiological responses to infrared stimulation of the vestibular neuroepithelium. Currently, she investigates inner earpathophysiology, focusing on trauma-induced vestibular dysfunctions. She aims to advance understanding in this field and contribute to the development of innovative therapeutic strategies for balance disorders.

About the Research

Characterization and Treatment of Occupational Noise-induced Vestibular Loss

Noise exposure is a major occupational hazard affecting millions of U.S. workers. While its impact on hearing is well-established, noise can also damage the vestibular system, which controls balance and spatial orientation. This condition, noise-induced vestibular loss (NIVL), increases the risk of falls and injuries but remains under-researched with few effective treatments.

Our study aims to address this gap by developing diagnostic tools to assess hearing and balance under realistic noise conditions in a preclinical setting. We will examine how NIVL affects different age groups, providing insights on how noise may affect older workers who face higher risks of balance impairment. Additionally, we will test novel therapeutic approaches targeting cell death and inflammatory pathways.

Overall, this research seeks to improve prevention and treatment strategies, enhancing workplace safety and quality of life for workers of all ages.

About the Researcher

Dr. Sushobhan Biswas, PhD, is a postdoctoral scholar in Dr. Taha Jan’s laboratory at Vanderbilt University Medical Center. He obtained his Ph.D. from the University of Calcutta (India) for his work studying the molecular mechanisms of neuronal death. His current research focuses on investigating the mechanisms of hair cell regeneration in mammals following injury to restore hearing and balance dysfunction. His objective is to investigate the early regenerative response of supporting cells following hair cell death in mammals using an in vivo damage model.

About the Research

Identification of Molecular Markers of Mammalian Hair Cells Regeneration

The major causes of both hearing loss and balance problems in humans is the permanent loss of mechanical receptor cells called hair cells. Once these hair cells are lost in mammals, they do not regenerate. These same hair cells also provide balance function in a neighboring organ called the utricle. Unlike the hearing organ, the utricle still has some limited ability to make new hair cells following injury. In this study, we use a mouse model to study this regenerative process in the utricle. We are looking to learn what cues are activated after damage that allow new hair cells to be formed. Our goal is to ultimately be able to push cells towards a regenerative phase in both the hearing and balance organs for functional restoration of these organs.

About the Researcher

Nathaniel Greene, PhD, is an Associate Professor in the Department of Otolaryngology Head and Neck Surgery at the University of Colorado School of Medicine (CU SOM, Aurora, CO). Dr. Greene earned a BA in Physics from Wittenberg University (Springfield, OH), an MS and PhD in Biomedical Engineering from the University of Rochester (Rochester, NY), and completed postdoctoral training in Physiology and Biophysics at CU SOM. Additionally, Dr. Greene has been employed studying audio-visual integration in the Department of Psychological and Brain Sciences at Dartmouth College (Hanover, NH), and hearing protection at the U.S. Army Aeromedical Research Laboratory (Ft. Novosel, AL).

About the Research

A Novel Method for Assessing Vestibular Injury to Sound and Vibration Exposure

Cochlear implants have the potential to provide hearing to individuals with severe to profound hearing loss. Unfortunately, some patients experience loss of residual hearing and balance function after implantation. Recent results from our laboratory suggest that the insertion of the implant array can cause “noise” which can injure the hearing and balance organs similar to the noise from a gunshot, but a direct link between this noise and the injury observed in patients has not been made to date. Current methods do not allow direct measurements of this noise in patients. To overcome this obstacle we aim to develop a novel animal model that duplicates the inner ear noise in human ears, and thereby quantitatively predicts the human injury. If successful, this program will validate this method for predicting human injury to noise and vibration exposure, and allow refinement of cochlear implant surgery to minimize injury.

About the Researcher

Junzhan Jing, PhD, is a postdoctoral associate trained in Dr. Xiaolong Jiang’s laboratory at Baylor College of Medicine, Houston. He received his Ph.D. in Physiology at Peking University, Beijing. His research focuses on uncovering and understanding novel cell types and their microcircuits across various brain regions, with an emphasis on the auditory brainstem. By employing multi-cell patch recordings, morphological recovery, single-cell RNA sequencing, spatial transcriptomics, and machine learning, he aims to investigate cell type-specific molecular and microcircuit changes underlying hearing disorders, providing deeper insights into auditory processing and neural circuit organization.

About the Research

Comprehensive Cellular and Molecular Profiling of the Cochlear Nucleus in Rhesus Monkeys: Insights into Auditory Processing and Disorders

The cochlear nucleus (CN) is the first stop for central auditory processing. While extensive studies on non-primates like rodents have defined cell types and circuit organization in CN, we still don’t know how these findings apply to humans. Unlike rodents, primates, including humans, have distinct hearing abilities and CN structure differences, suggesting primates have unique auditory circuits. However, the cellular composition and organization of the primate CN are largely unknown. This project will address this gap by using single-nucleus RNA sequencing and spatial transcriptomics to study CN tissue from rhesus monkeys. In addition, comparing the findings with data from mice will reveal both shared and species-specific features of CN organization. The study will provide insights into human hearing, help improve the design of auditory brainstem implants, and guide treatments for hearing disorders.

About the Researchers

Yuvraj Joshi, PhD, received his PhD in Health Biology from the Institute of Neurosciences, University of Montpellier, France, where he studied the mechanism underlying progressive hearing loss in DFNA25 deafness. He then worked as a postdoctoral researcher at the Karolinska Institute in Stockholm, Sweden, exploring the underlying mechanism of age-related hearing loss in mice. He is currently a postdoctoral fellow in Savas Lab at Northwestern University. His research focuses on investigating the mechanisms underlying hearing impairment caused by cochlear aging and noise exposure, with particular emphasis on the proteomic changes induced by loud external noise in mice. 

Jeffrey Savas, PhD, earned his BS in Biochemistry and Molecular Biology from the University of California, Santa Cruz. He received his PhD from New York University School of Medicine, followed by postdoctoral training at The Scripps Research Institute. In 2015, he established the Savas Lab at Northwestern University. Our research aims to deepen our understanding of mechanisms driving neurodegeneration in the central and peripheral nervous systems. Specifically, the lab investigates how impaired protein homeostasis contributes to dysfunction in long-lived cells that cannot be replenished through cell division. To achieve these objectives, we use biochemistry, chemical biology, and mass spectrometry-based proteomic analysis. 

About the Research

The Role of Extremely Long-Lived Proteins in Acquired Hearing Loss

Sensorineural hearing loss (SNHL) affects over 460 million people worldwide, and is caused by damage to sensory cells, nerves, and membranes in the inner ear. A common cause is exposure to loud noise, leading to noise-induced hearing loss (NIHL). NIHL develops gradually, leading to reduced hearing sensitivity, as well as difficulties in noisy environments and the onset of tinnitus. 

The mechanisms underlying NIHL, and age-related hearing loss remain unclear. The damage-based aging theory suggests that environmental factors cause harmful molecules to accumulate, leading to cellular and organ dysfunction. A key aspect of this process is protein turnover, where most proteins are replaced regularly, but extremely long-lived proteins (ELLPs) persist for months or years. ELLPs accumulate damage over time, contributing to aging. Our research suggests the cochlea contains many ELLPs, and we aim to investigate whether damage to these proteins due to noise exposure and aging contributes to hearing loss. 

About the Researchers

Elin Roverud, AuD, PhD, CCC-A, received her Au.D. and Ph.D. degrees from Purdue University and completed post-doctoral training at Boston University. She currently is a Research Assistant Professor at Boston University.  Her research work is in the area of psychoacoustics, with a special focus on investigations related to hearing loss effects in the “cocktail party” and selective auditory attention abilities in listeners with normal hearing and listeners with hearing loss.  

Dr. Tyler Perrachione, PhD, is the Director of the Hearing Research Center and Associate Professor of Speech, Language, and Hearing Sciences at Boston University. He holds a PhD in Neuroscience from MIT and previously studied linguistics and cognitive sciences at Northwestern University. Dr. Perrachione’s research program aims to understand the neural systems for speech communication, how they are disrupted in communication disorders, and how they can be enhanced to facilitate learning and rehabilitation. To these ends, his research group employs behavioral, neuroimaging, and neuromodulatory techniques, including psycholinguistics, psychoacoustics, functional and structural MRI, EEG, pupillometry, and noninvasive brain stimulation. 

About the Research

Comparing effects of transcranial direct current stimulation and transcranial alternating current stimulation during auditory training for listeners with hearing loss struggling with speech-on-speech understanding

Many people with sensorineural hearing loss have trouble understanding speech when more than one person is talking. Auditory training in which people practice recognizing speech in background speech can lead to improvements, but these benefits can be small or variable across listeners.  Recent studies show that one type of noninvasive brain stimulation (transcranial alternating current stimulation; tACS) can lead to improved speech understanding in noise during stimulation. However, it is not known if these benefits persist beyond the stimulation period, if these effects can enhance benefits from auditory training, or if another type of noninvasive brain stimulation (transcranial direct current stimulation; tDCS) also may lead to benefits in these areas. This project compares effects of tACS and tDCS relative to placebo stimulation in how well people with hearing loss understand speech in the presence of background speech during and after the stimulation period.

About the Researcher

Takashi Sato, MD, PhD, obtained his medical degree from the University of Tokyo and his Ph.D. from Vanderbilt University. After completing his postdoctoral training at Janelia Research Campus, he served as a Junior Group Leader at the University of Tübingen before joining the Medical University of South Carolina. The research of the Sato Lab focuses on sensory-motor processing in the brain, with an emphasis on eye movements and forepaw movements (e.g., Hasegawa et al., Cell Rep, 2017; Itokazu et al., Nat Commun, 2018). The lab is applying its expertise in imaging techniques and mouse behavior to unravel vestibular information processing.

About the Research

Neural Basis for Motion Induced Sickness in Mice

This research focuses on understanding how the brain processes signals from the inner ear, which plays a crucial role in controlling balance and detecting movement. These signals are vital for stabilizing vision and maintaining posture. Using advanced imaging technology, the study will examine how the brainstem processes signals from head movements and shares them with other parts of the brain. By studying how different
neurons in the brainstem respond to head movements, the research aims to uncover the mechanisms behind balance disorders such as vertigo and motion sickness. Ultimately, this study will provide new insights into how the brain processes balance-related information, with potential implications for improving treatments for balance and motion-related disorders, including motion sickness and Meniere’s disease.

About the Researcher

Pavan S. Krishnan, MD is an otolaryngology-head and neck surgery resident in the NIDCD R25 program at the University of Miami. He previously attended Virginia Commonwealth University School of Medicine and spent a year in Dr. John Carey’s laboratory at Johns Hopkins investigating biomarkers for vestibular migraine. He is interested in understanding the molecular mechanisms of vestibular disorders and developing novel therapeutic strategies for vestibular dysfunction. He is spending his R25 year in Dr. Suhrud Rajguru’s NeuroTherapeutics laboratory studying the vestibular system in the context of a blast injury model and the role of mild therapeutic hypothermia.  

About the Research

Mechanisms of Vestibular Injury and Therapeutic Hypothermia Post-Blast

Individuals exposed to blasts in combat and civilian environments most commonly report audiovestibular symptoms that often last months after the initial incident. Unfortunately, the effects of blasts on the peripheral vestibular system have not been well-studied even in preclinical models. Further, there are no known strategies for diagnosing and managing post-blast vestibular dysfunction. Using a preclinical rodent model, we will determine the mechanism of injury in the vestibular endorgans at acute time points and evaluate the efficacy of mild therapeutic hypothermia in mitigating post-blast functional and behavioral effects. Elucidating the mechanism of damage can offer further options for future therapeutic targets. Ultimately, our data will help the clinical and scientific community determine the best possible diagnostic and treatment strategies for those affected. 

About the Researcher

Carly Misztal, MD is a third-year otolaryngology resident at the University of Miami and Jackson Health System. Her research interests include the vestibular schwannoma tumor microenvironment, clinical outcomes in cochlear implantation, and the role of perineural invasion in head and neck squamous cell carcinoma. 

About the Research

Effect of Hypoxia on the Vestibular Schwannoma Tumor Microenvironment

Vestibular schwannomas, benign tumors of the hearing and balance nerve, can cause significant hearing loss, dizziness, and intracranial complications. Existing treatment modalities for these tumors also have significant side effects that may negatively impact quality of life. Hypoxia, or low oxygen levels, occurs when tumors outgrow their blood supply, changing cellular metabolism and behavior. Hypoxia has been well-studied in cancer, but the effects of hypoxia in vestibular schwannomas is not known. With this project, we will examine the effects of hypoxia on patient-derived vestibular schwannoma cells. We will additionally assess the effect of hypoxia on the tumor microenvironment and evaluate how cellular behavior relates to a patient’s clinical features to pave the way for the identification of targeted pharmacotherapies for vestibular schwannoma.