Meniere's Disease Research Laboratory
Lab head: Daniel Brown
Location: The Brain & Mind Research Institute
This laboratory researches the cause of Meniere's Disease, a hearing and balance disorder characterized by random attacks of severe vertigo and fluctuating hearing loss.
It is currently thought that an abnormal volume of fluid in the inner ear called "endolymphatic hydrops" that can be seen in MRI scans causes a displacement of the inner ear hair cells that sense sound and orientation.
We are investigating the effects of endolymphatic hydrops, with the ultimate goal of understanding the mechanisms that lead to its production so that a cure can be developed.
Research approach equipment: In vivo electrophysiological studies in guinea pigs are used to investigate the effects of abnormal fluid volumes on inner ear function. These studies include conventional measurements of extracellular hair cell and neural electrical and mechanical responses to sound from the cochlea, as well as the development of novel measurement techniques for assessing vestibular hair cell responses to head rotations and displacements. The aim is to obtain simultaneous measurements of cochlear and vestibular hair cell displacement and function during various experimental manipulations that mimick Meniere's Disease.
Patuzzi, R.B., Brown, D.J., McMahon, C.M., Halliday, A.F. Determinants of the spectrum of the neural electrical activity at the round window: transmitter release and neural depolarisation. Hear Res. 2004.190(1-2): 87-108. PMID: 15051132
McMahon, C.M., Brown, D.J., Patuzzi, R.B. Transient focal cooling at the round window and cochlear nucleus shows round window CAP originates from cochlear neurones alone. Hear Res. 2004. 190(1-2): 75-6. PMID: 15051131
Brown, D.J., McMahon, C.M., Patuzzi, R.B. K+ currents produce P1 in the RW CAP: evidence from DC current bias, K+ channel blockade and recordings from cochlea and brainstem. Hear Res. 2004. 190(1-2): 60-74. PMID: 15051130
Brown DJ, Hartsock JJ, Gill RM, Fitzgerald HE, Salt AN. 2009. Estimating the operating point of the cochlear transducer using low-frequency biased distortion products. J Acoust Soc Am. 125(4):2129-45. PMID: 19354389
Salt AN, Brown DJ, Hartsock JJ, Plontke SK. 2009. Displacements of the organ of Corti by gel injections into the cochlear apex. Hear Res. 250(1-2):63-75. PMID: 19217935
Brown, D.J., Patuzzi R.B. 2010. Evidence that the compound action potential (CAP) from the auditory nerve is a stationary potential generated across dura mater. Hear Res. 2010 Apr 26. [ahead of print] PMID: 20430085
The Use of Vestibular Microphonic as a Measure of Semicircular Canal Hair Cell Displacement
Primary supervisor: Daniel Brown
Ménière’s Disease is a hearing and balance disorder characterized by random episodes of severe vertigo, fluctuating hearing loss, tinnitus and the overall decline in function of the effected ear, and it afflicts almost 50,000 Australians. While it's currently thought that an abnormal volume of fluid in the inner ear is involved in the symptoms of this disease, it is still unclear how, or if, this abnormal volume of fluid changes the function of the vestibular system. While numerous techniques are available for monitoring cochlear hair cell function during experimentation, novel measurements of vestibular function are required to determine the cause of Ménière’s Disease. The development of these techniques will involve in vivo electrophysiological animal studies, focusing on responses to sound and movement.
Keywords: Ear & hearing diseases, Otolaryngology, Physiology, Vestibular