I investigate the anatomy, physiology and pathology of the inner ear.
At least 30 million Americans are exposed to hazardous levels of noise on a daily basis. All these people are at risk for developing noise-induced hearing loss (NIHL). The hearing loss which is caused by listening to loud sounds adds to that resulting from aging (i.e., presbycusis) and exposure to ototoxic drugs such as aminoglycoside antibiotics and platinum compounds. Moderate-to-severe permanent hearing impairment is devastating in all aspects of life, including the ability to communicate effectively with others, maintain employment, and enjoy some of the greatest pleasures in life such as the human voice, music and the sounds of nature. An important step in developing strategies to prevent or treat NIHL involves determining how noise actually destroys the different cell types in the cochlea.
My research focus is on the phenomena of degeneration and repair in the mammalian peripheral auditory system. The chinchilla and mouse serve as animal models. Exposure to noise and "natural" aging are the agents which are used to create inner-ear lesions in order to study these phenomena. Auditory function is determined before and several times after the experimental treatment. In all animals, auditory brainstem responses (ABRs) in response to tone pips and clicks and distortion product otoacoustic emissions (DPOAEs) in response to pairs of tones are recorded. After completion of the functional studies, the animals' ears are prepared for detailed microscopic examination, including by transmission electron microscopy (TEM). Quantitative data on the magnitude and pattern of hair cell, supporting cell and nerve fiber loss are collected from plastic-embedded flat preparations of the cochlear duct. These data are correlated with the post-exposure changes in auditory function. Areas in the damaged organ of Corti are subsequently semi-thin and thin-sectioned for bright-field and TEM.
Research Photos (Click to Enlarge)
Research Publications
Harding GW, Bohne, BA. Noise-induced hair-cell loss and total exposure energy: Analysis of a large data set. J Acoust Soc Am. 2004; 115:2207-2220.
Ahmad M, Bohne BA, Harding GW. An in vivo tracer study of noise-induced damage to the reticular lamina. Hear Res. 2003; 175:82-100.
Harding GW, Bohne BA, Ahmad M. DPOAE level shifts and ABR threshold shifts compared to detailed analysis of histopathological damage from noise. Hear Res. 2002; 174:158-171.
Bohne BA, Harding GW. Degeneration in the cochlea after noise damage: primary versus secondary events. Am J Otol. 2000 Jul;21(4):505-9.
Ou HC, Harding GW, Bohne BA. An anatomically based frequency-place map for the mouse cochlea. Hear Res. 2000 Jul;145(1-2):123-9.
Nordmann, AS, Bohne, BA & Harding, GW: Histopathological differences between temporary and permanent threshold shift. Hear Res, 139:13-30, 2000.
Contact Info
Barbara Bohne, Ph.D.
Office Location: 1141 Shriner's Hosp
Office Phone: 314-362-7497
Campus Box: 8115
Fax: 314-362-7497
bohneb@ent.wustl.edu
http://oto.wustl.edu/bbears/bohne1.htm
