Prof David Ryugo

Lab Head - Hearing Research

Senior Principal Research Fellow

Conjoint/Adjunct Role(s)

Conjoint Professor, School of Medical Sciences, UNSW Australia
Principal Honorary Fellow, Bionics Institute, Melbourne, VIC, Australia
Honorary Member, Department of Otolarynogology, Head, Neck and Skull Base Surgery, St Vincent’s Hospital, Darlinghurst, NSW
Professor Emeritus, Johns Hopkins University School of Medicine, Baltimore, MD USA

I grew up in a small college town in northern California that centered around agriculture. I enjoyed sports, woodworking, hiking and camping, and was drawn to mathematics and science because of my interest in problem solving. I value education, love my work, and consider preservation of the environment mankind’s greatest challenge.

I earned a bachelors degree in psychology from Yale University and a PhD in biological sciences from the University of California, Irvine.  I spent 9 years on the faculty at Harvard Medical School and 23 years at Johns Hopkins University School of Medicine before retiring as professor emeritus and joining the Garvan.  My research focuses on understanding brain mechanisms of hearing, and I study structure-function relationships in neuronal circuits of the auditory system.  I am especially interested in how deafness and hearing loss alter brain organization, and in exploring strategies for hearing restoration.

Research Interests

Brain mechanisms of hearing
Role of neural activity on brain development
Synaptic plasticity

Awards and Honours

2011 - Professor Emeritus, Johns Hopkins University School of Medicine, Baltimore, MD
2010 - Curran Foundation Professor, Garvan Institute, Darlinghurst, NSW
2007 - Creighton University Distinguished Lecturer Award
1991-98 - Claude Pepper Neuroscience Investigator Award, NIH/NIDCD
1986 - Faculty Prize for Excellence in Teaching, Harvard Medical School, Boston, MA
1976 - UC Irvine Alumni Association Award for Outstanding Graduate Research, Irvine, CA
1963 - Eagle Scout, Post 199, Davis, CA


1976 - PhD in Biological Sciences, University of California, Irvine, CA - USA
1970 - BA in Psychology, Yale University, New Haven, CT - USA

Selected Publications

Ryugo, D.K. and G.A. Spirou. Giant Synaptic Terminals: Endbulbs and Calyces of the Auditory System.  In: Neuroscience and Biobehavioral Psychology (Ed. J. Stein).  2016; Elsevier, New York (in press)

Suthakar,K. and D.K. Ryugo. Descending Projections from the Inferior Colliculus to Medial Olivocochlear Efferents: Mice with Normal Hearing, Early Onset Hearing Loss, and Congenital Deafness.  Hearing Res. 2016; (in press)

Muniak, M., C.J. Connelly, K. Suthakar, G. Milinkeviciute, F.E. Ayeni, and D.K. Ryugo.  Central Projections of Spiral Ganglion Neurons.  In: The Primary Auditory Neurons of the Mammalian Cochlea (eds. A. Dabdoub, B. Fritzsch, A.N. Popper, and R.R. Fay).  2015; Springer-Verlag, New York, pp. 157-190. 

Ryugo, D.K. Auditory neuroplasticity, hearing loss and cochlear implants.  Cell Tissue Res. 2015; 361:251-269.

McGuire, B., B. Fiorillo, D.K. Ryugo, and A.M. Lauer. Auditory nerve synapses persist in ventral cochlear nucleus long after loss of acoustic input in mice with early-onset progressive hearing loss.  Brain Res. 2015; 1605:22-30.

David, V.A., M. Menotti-Raymond, A.C. Wallace, M. Roelke, J. Kehler, R. Leighty, E. Eizirik, S.S. Hannah, G. Nelson, A.A. Schäffer, C.J. Connelly, S.J. O'Brien, and D.K. Ryugo. Endogenous retrovirus insertion in KIT oncogene determines White and White Spotted in domestic cats.  G3 (Bethesda) 2014; 4(10)1881-1891.  

Ryugo, D.K. From Degenerative Debris to Neuronal Tracing: An Anterograde View of Auditory Circuits.  In: Auditory Neuroscience: Perspectives and Prospectives (eds. A.N. Popper and R.R. Fay).  2014; Springer-Verlag, New York, pp 513-530.  

Muniak, M.A., and D.K. Ryugo.  Tonotopic organization of vertical cells in the dorsal cochlear nucleus of the CBA/J mouse.  J. Comp. Neurol. 2014; 522(4):937-949.    

Fallon, J.B., D.K. Ryugo, R.K. Shepherd. Consequences of deafness and electrical stimulation on the peripheral and central auditory system.  In:  Cochlear Implants: Third Edition, (eds. S.B. Waltzman and J.T. Roland).  2013; Thieme Medial Publishers Inc., New York, NY, pp 25-39.

Muniak, M.A., C.J. Connelly, N.N. Tirko, J.N. O’Neil, and D.K. Ryugo.  Synaptic Organization and Plasticity in the Auditory System.  In: Deafness (eds. A. Kral, A.N. Popper, R.R. Fay).  2013; Springer-Verlag, New York, pp 83-128.    

Muniak, M.A., A. Rivas, K.L. Montey, B.J. May, H.W. Francis and D.K. Ryugo. A 3-dimensional model of frequency representation in the cochlear nucleus of the CBA/J mouse.  J. Comp. Neurol. 2013; 521:1510-1532.

Lauer, A.M., C. Connelly, H. Graham, and D.K. Ryugo (2013)  Morphological characterization of bushy cells and their inputs in the laboratory mouse (Mus musculus) anteroventral cochlear nucleus.  PLoS One 8:1-16. 

Ryugo, D.K. and M. Manetti-Raymond (2012)  Feline deafness. Vet Clin North Am Small Anim Pract. 46:1179-1207.

Nayagam, B.A., M.A. Muniak, and D.K. Ryugo (2011)  The spiral ganglion: connecting the peripheral and central auditory nervous systems. Hear. Res. 278:2-20.

Hancock, K.E., N. Victor, D.K. Ryugo, and B. Delgutte (2010)  Neural coding of interaural time differences with bilateral cochlear implants: Effects of congenital deafness.  J. Neurosci. 30:14068-14079.

Ryugo, D.K. (2008) Projections of low spontaneous rate, high threshold auditory nerve fibers to the small cell cap in the cochlear nucleus of cats.  Neuroscience 154:114-126.

Eisen, M.D., and D.K. Ryugo (2007) Hearing molecules: Contributions from genetic deafness.  Cell. Mol. Life Sci. 64:566-580. Review.

Ryugo, D.K., E.A. Krezmer, and J.K. Niparko (2005)  Restoration of auditory nerve synapses by cochlear implants.  Science  310:1490-1492.

Ryugo, D.K., and T.N Parks (2003)  Innervation of the cochlear nucleus in birds and mammals.  Brain Res. Bull. 60:435-456.

Ryugo, D.K., B.T. Rosenbaum, P.J. Kim, J.K. Niparko, and A.A. Saada (1998)  Single unit recordings in the auditory nerve of congenitally deaf white cats: Morphological correlates in the cochlea and cochlear nucleus.  J. Comp. Neurol. 397:532-548. 

Ryugo, D.K., M.M. Wu, and T. Pongstaporn (1996)  Activity-related features of synapse morphology: A study of endbulbs of Held.  J. Comp. Neurol. 365:141-158.

Fekete, D.M., E.M. Rouiller, M.C. Liberman, D.K. Ryugo (1984)  The central projections of intracellularly labeled auditory nerve fibers in adult cats.  J. Comp. Neurol. 229:432-450.

Kiang, N.Y.S., J.M. Rho, C.C. Northrup, M.C. Liberman, D.K. Ryugo (1982) Hair-cell innervation by spiral ganglion cells in adult cats.  Science 217:175-177.

Prof David Ryugo