Donald Caspary, PhD

Research Professor, Department of Pharmacology

    About me



    Professional Experience:

    Southern Illinois University School of Medicine, Springfield, IL, Distinguished Scholar and Res. Professor of Pharmacology & Surgery 2012-

    Southern Illinois University School of Medicine, Springfield, IL, Distinguished Scholar and Professor of Pharmacology, 2004-2012

    Research Interest and Specialties:

    Recent Research Activities in the Caspary Auditory Neurobiology Laboratory

    Aging: Age-related hearing loss impacts 30-50% of individuals over 65 years of age. An age-related loss of speech understanding causes many elderly, cognitively intact, individuals to withdraw from active participation in society.  Our recent studies focused on the nature of inhibitory receptors and how they influence processing of acoustic information in the auditory thalamus (MGB). We specifically characterized role of extrasynaptic GABAA receptors in the auditory thalamus. We described the properties of the tonic currents mediated by these receptors using molecular neurochemistry and slice recordings from adult and aged animals. These studies describe a profound (50%0 age-related loss in the number and function of extrasynaptic GABAA receptors in auditory thalamus.

    Tinnitus: Aside from studies on the impact of aging the Auditory Neurobiology Laboratory examines animal models of tinnitus. This “ringing in the ears” affects 10% of the general population and an overwhelming number of military personnel. In a parallel series of studies on extrasynaptic GABAA receptors in animals with tinnitus, we found an increase in the sensitivity of these receptors. These tinnitus results, support the thalamocortical dysrhythmia hypothesis underpinning tinnitus pathology at the level of thalamus. Recordings from awake rat auditory thalamus showed increased spontaneous activity and increased sound-evoked activity in neurons in MGB of animals with tinnitus. Many tinnitus-related response changes correlated directly with the tinnitus score of the individual animal. Animals showing more tinnitus, showed more bursting and more spontaneous activity, etc.

    Role of Cholinergic Receptors in Aging and Tinnitus: Recent work has focused on cholinergic inputs to the auditory thalamus. When a signal is difficult to detect or unusual, brainstem cholinergic neurons are activated by descending pathways from the auditory cortex and the hippocampus. The present studies attempt to identify the location and age-related changes of nicotinic cholinergic receptors in the auditory thalamus.

    Animal Models of Auditory Processing: Understanding the role of bottom-up and top-down processing of acoustic information is critical to understanding age-related loss of speech understanding. Collectively these studies of plasticity in models of tinnitus and aging will both in vitro and in vivo electrophysiologic methods with a range of molecular neurochemical and imaging techniques to address these important neuroscience questions.


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    Education & training

    Doctorate Degree
    PhD, New York University, Biology/Neurobiology
    Graduate Degree
    MS, Syracuse University, Zoology/Sensory Communication
    Undergraduate Degree
    B.A., University of Wisconsin, Zoology


    Chronic sound-induced tinnitus and auditory attention in animals

    T Brozoski, K Wisner, M Randall, D Caspary    
    Neuroscience 407, 200-212

    Nicotinic receptor subunit distribution in auditory cortex: Impact of aging on receptor number and function

    M Ghimire, R Cai, L Ling, TA Hackett, DM Caspary  
    Journal of Neuroscience 40 (30), 5724-5739

    Corticothalamic projections deliver enhanced responses to medial geniculate body as a function of the temporal reliability of the stimulus

    SP Kommajosyula, EL Bartlett, R Cai, L Ling, DM Caspary 
    The Journal of physiology 599 (24), 5465-5484

    Neuronal nicotinic acetylcholine receptor partial agonists as therapeutics for chronic tinnitus

    D Caspary, T Brozoski, B Cox 
    US Patent App. 17/428,164

    Mechanisms of GABAergic and cholinergic neurotransmission in auditory thalamus: Impact of aging

    BD Richardson, SY Sottile, DM Caspary 
    Hearing research 402, 108003

    Desensitizing nicotinic agents normalize tinnitus-related inhibitory dysfunction in the auditory cortex and ameliorate behavioral evidence of tinnitus

    M Ghimire, R Cai, L Ling, KA Brownell, KW Wisner, BC Cox, TA Hackett, ... 
    Frontiers in Neuroscience 17, 1197909

    Increased Pyramidal and VIP Neuronal Excitability in Rat Primary Auditory Cortex Directly Correlates with Tinnitus Behavior

    M Ghimire, R Cai, L Ling, KA Brownell, TA Hackett, DA Llano, ... 
    The Journal of physiology

    Click here to see entire publication list. 


    Grants Received (Active):

    DOD-Congressionally Directed Medical Research Programs; PR180160 - Nicotinic Receptor in Tinnitus: Auditory Cortex and Selective Desensitizing Nicotinic Agents, $391,754 ADC, 9/1/19 - 8/31/22, Principal Investigator

    National Institutes of Health NIDCD, RO1 DC00151- Coding in Auditory Neurons: Effects of Amino Acids, $2.4M 12/1/23 - 11/31/28, Principal Investigator (Years 38-43)

    Office of Naval Research, Targeting attentional mechanisms in tinnitus, $879,325, 4/22/16 - 4/21/19, Principal Investigator


    Founders Day Award, New York University, New York

    Certificate of Merit, American Speech and Hearing Association

    Advisor to the Committee on Hearing and Bioacoustics, National Academy of Science

    Claude Pepper Award from the National Institute on Deafness and Other Communicative Disorders

    Council Member, Association for Research in Otolaryngology

    Member, Board of Directors, Center for Neural Communication Technology-University of Michigan

    Nineteenth Outstanding Scholar, Southern Illinois University, 2003

    Distinguished Scholar, Southern Illinois University, 2004

    Sigma Xi Kaplan Research Award, 2005

    Life Science Innovator, Illinois Biotechnology Industrial Organization-2006

    Teacher of the Year, Southern Illinois University School of Medicine, 2009

    Guest Editor: Special Issue of Hearing Research- Aging and Hearing, 2010

    Board Member, Tinnitus Research Consortium, 2005-2016

    Scientific Advisory Committee, American Tinnitus Association, 2005-2012

    Related articles

    Lynne Ling

    Ling receives 2023 Toth Award for research support

    The Research Policy Committee honored Lynne Ling with the 2023 Frank J. Toth Award, the highest recognition for SIU School of Medicine research support personnel. Ling is lab manager in the Auditory Neurobiology Laboratory in the pharmacology department.
    Caspary lab crew

    A study in longevity: Dr. Don Caspary earns new 5-year NIH grant

    His latest NIH grant marks an incredible 38-year run of federal funding for Dr. Don Caspary’s scientific studies of auditory signaling in the brain.