Research & Faculty
Hearing research group
Hearing disorders of many types begin in the inner ear, but have long-term effects in the brain. The Hearing Research Group at NEOMED seeks to deepen the understanding of how the central nervous system functions in association with hearing, communication and swallowing, how it is affected by hearing disorders, and how manipulation of the central nervous systems may improve these disorders.
Areas of Study
Tinnitus is a ringing or similar sensation of sound in the ears. Research is being conducted to see if hearing loss and tinnitus are the result of abnormal nerve cell changes that occur due to aging or early noise exposure.
Studies the nerve or nervous system mechanisms responsible for auditory neuron response to complex sounds.
Studying how emotional centers in the brain interpret the meaning of speech-like sounds and the mechanism by which communication sounds are misinterpreted in disorders such as post-traumatic stress, autism, and fetal alcohol syndrome.
Studies investigate why some people are better than others at learning to perceive speech and other sounds. Research focuses on changes in auditory perception during adolescence and looking at biological and cognitive facors such as attention and memory.
Research investigate the fuctions and make up of proteins in auditory processing under normal hearing and hearing loss conditions.
Studying how infections and early experiences change the brain and may affect hearing loss.
Acetylcholine and GABA are chemicals used for communication between nerve cells. They are important in many aspects of hearing, including selective attention, learning and understanding speech. Research is being conducted to understand how these chemicals contibute to brain development.
Professor and Chair of Anatomy and Neurobiology
Our laboratory studies neural mechanisms underlying hearing and acoustically guided behaviors, particularly social communication. We have focused increasingly on interactions between hearing and emotions. Much of our current work examines three facets of these interactions: the link between vocal signals and an animal’s emotional state, the analysis of social vocalizations by emotional centers in the brain, and the manner in which emotional centers modify processing of sounds by the auditory system. We use a wide variety of approaches in our work—acoustic, behavioral, neurophysiological, pharmacological, and anatomical. We are particularly excited about technical developments that will allow us to analyze the activity of individual neurons during social interactions. Our work on the basic neural mechanisms forms the basis for future studies of disorders of acoustic communication that involve misinterpretations of the meaning of sounds.
We thank the National Institute for Deafness and other Communication Disorders for their support of this work.
Director, Translational Research Center
Professor of Anatomy and Neurobiology
Focusing on the auditory system, Dr. Bao’s research group has been studying whether two ‘opposite disorders’, hearing loss and tinnitus, are both the result of abnormal synaptic changes that occur due to aging or early noise exposure. This group has been working to understand basic cellular and molecular mechanisms underlying these abnormal changes, employing a variety of molecular, behavioral, electrophysiological, and imaging methods. At the same time, the group has also explored translational opportunities to treat these disorders with pharmacogenomic approaches and stem cell therapies. Recently, the group discovered an effective means for eliminating or delaying hearing loss with drugs that are already approved by the U.S. Food and Drug Administration (FDA) for other indications. With funding from both the National Institutes of Health (NIH) and other sources, the group continues to explore basic mechanisms underlying these age-related disorders and other sources, the group continues to explore basic mechanisms underlying these age-related disorders and simultaneously develop both drug and stem cell therapies to treat these common diseases.
Based on recent seminal preclinical studies from Dr. Bao’s research group showing that antiepileptic drugs that block calcium channels effectively diminish presbycusis, a collaborative research project has been established to test whether the severity of age-related hearing loss is correlated with specific genetic variants in genes encoded for calcium signaling as well as whether causal genetic variants in the same genes associated with better hearing can be determined in elderly persons taking calcium channel blockers. The long-term goal of this project is to develop a personalized medical intervention for presbycusis. The innovative aspect of this study is to apply pharmacogenetic approaches to discover personalized medications to prevent presbycusis.
In addition to Dr. Bao’s research group, a multidisciplinary team has been assembled that includes: Dr. Zhenyu Jia and Mike Hewit of NEOMED; Drs. Cliff Megerian, Gail Murray, and Qing Yin Zheng from Case Western Reserve University School of Medicine; and Drs. Nancy Tye-Murray and Jay F. Piccirillo from Washington University School of Medicine. This project represents a unique opportunity that brings together a diverse team for the purpose of conducting translation research to improve health outcomes of patients at risk for presbycusis.
Associate Professor of Anatomy and Neurobiology
We study neural mechanisms underlying complex sound processing in the auditory system of echolocating bats, which are known to have excellent hearing. At the same time many features of their sonar sounds are analogous to other communication sounds including human speech. Physiological studies in bats can therefore provide insight into how speech-like sounds are encoded in the auditory system. The major focus of our research is to examine mechanisms responsible for auditory neuron response selectivity to different parameters of complex sounds. Among different neurophysiological approaches we use in our laboratory, our primary electrophysiological technique involves intracellular recording of single auditory neurons in awake bats in response to sounds.
Associate Professor of Anatomy and Neurobiology
Our current research interests encompass three areas 1) Functions of G-protein-coupled receptors in auditory information processing; 2) Development of neuronal properties of central auditory neurons; and 3) Cellular mechanisms underlying sound localization.
Electrophysiological (e.g. whole-cell recordings) and cell imaging approaches, combined with pharmacological tools, are employed. Our work aims to help lay the groundwork for decisions about possible therapeutic approaches to hearing defects such as tinnitus and hearing loss.
Assistant Professor of Anatomy and Neurobiology
We are interested in the development of auditory perception and its underlying neural coding in the auditory system. In particular, we study how neural circuits and perceptual abilities are influenced by hearing loss and auditory experience over time. The lab examines neural activity underlying the perception of natural and artificial sounds, as well as vocal communication calls, in the Mongolian gerbil. To do so, we record from implanted arrays of electrodes in animals of different ages while they perform behavioral discrimination tasks. We use intracellular in vivo recordings to identify changes in local circuits that are associated with hearing loss and maturation. Computational analyses of the data assess alterations in neural coding that correlate with perceptual deficits and maturational changes.
Professor of Anatomy and Neurobiology
We study brain circuits used to analyze sounds. The brain processes auditory information in ascending circuits that extend from the ear to the cerebral cortex, where sound is perceived. Descending pathways allow higher centers (e.g., cortex) to modify neural processing in the lower centers. This modification is important for many functions, such as selective attention and discrimination of sounds in a noisy environment.
Our primary subject is the guinea pig, a small mammal with well-developed hearing and well-differentiated auditory circuits. We use a variety of anatomical tracers to label specific neural pathways. We then examine these pathways in the light and electron microscopes to identify the cell types and their interconnections. We also combine these methods with immunohistochemical techniques to identify the neurotransmitters used by different circuit components.
Research Assistant Professor of Anatomy and Neurobiology
What are the mechanisms by which information is encoded in the brain and how is this information used? These two questions form the basis of my research. I am currently exploring the representation of social vocalizations by neurons in the amygdala. I also have a long-standing interest in the coding of spatial information by the auditory system.