Academic Background

BA, University of New Hampshire, 1977
PhD, University of North Carolina, 1983
Postdoctoral Fellow, University of Pennsylvania, 1985
Assistant Professor, Medical University of South Carolina, 1985-87
Assistant/Associate Professor, Boston University School of Medicine, 1987-1997
Associate Professor, Children’s Hospital Boston/Harvard Medical School, 1998-2008
Affiliated Faculty Harvard/MIT Division of Health Sciences & Technology, 2002-2013
Associate Professor, Boston University School of Medicine, 2008-2010
Visiting Scientist, Harvard School of Public Health, 2010-2013

Cochlear Hair Cell Development and Regeneration

Research Interests

Research in my laboratory over the last twenty-five years has focused on the development, apoptotic death, and regeneration of sensory hair cells in the avian and mammalian cochlea. In 1986 I discovered that the chicken cochlea is capable of regenerating functional hair cells following noise exposure to replace those that have been lost or damaged due to acoustic trauma. This was quite a surprising finding at the time because previous research had indicated that lost hair cells were irreplaceable and resulted in permanent hearing deficits. Since my initial findings, hair cell regeneration has become the focus of a number of major laboratories throughout the world and has rapidly developed into a clinically relevant and competitive research area. It is believed that an understanding of avian hair cell regeneration will lead directly to clinical applications that can treat genetic, trauma-induced, or age-related hearing loss in humans.

Recent research projects in my laboratory addressed the mechanisms that regulate hair cell regeneration, i.e., the control of hair cell death, the subsequent proliferation of the supporting cells and the eventual differentiation of new hair cells in the avian cochlea. Normally, the sensory epithelium is composed of a postmitotic population of hair cells and supporting cells. Sound damage and aminoglycoside treatment were utilized experimentally to induce the loss of hair cells through apoptosis, or programmed cell death. The loss of hair cells from the sensory epithelium acts as a signal to re-initiate the cell cycle in the quiescent supporting cells.
Our research also explored the transplantation of neural stem cells into the damaged mammalian cochlea. We have transplanted mouse neural stem cells into the noise-damaged cochleae of mice and guinea pigs and have shown that the mouse stem cells integrate primarily into the cochlear ganglion where they differentiate into nerves and glial cells, but that they also reach the cochlea where they differentiate into hair cells and supporting cells.

From 2010 to 2013 I worked in the NIHL Research Group at the Harvard School of Public Health focusing on the impact of noise-induced hearing loss on the performance of Navy Sailors and Marines in military environments. We were exploring the bioavailability of systemically-administered antioxidants and their ability to attenuate hearing threshold shifts. We were also utilizing a genome-wide association research approach (GWAS) to investigate the role of small nucleotide polymorphisms (SNPs) in genes related to hearing protection and determining whether these gene mutations lead to an increased sensitivity to hearing loss. In addition, I have been working on a project on the interactions between cancer cells and host stroma cells in melanoma tumor growth and development in a mouse model.

My teaching responsibilities for the last 12 years were in HST 010 Functional Human Anatomy where I was the Acting Director of the course in 2011 and the Co-Director in 2012. I am now the Co-Director of the DSF course at UMass and teach in the Gross Anatomy lab.