Peter Dallos

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Peter Dallos (born November 26, 1934) is the John Evans Professor of Neuroscience Emeritus, Professor Emeritus of Audiology, Biomedical Engineering and Otolaryngology at Northwestern University. His research pertained to the neurobiology, biophysics and molecular biology of the cochlea. This work provided the basis for the present understanding of the role of outer hair cells in hearing, that of providing amplification in the cochlea. After his retirement in 2012, he became a professional sculptor.

Contents

Biography

An only child, Dallos was born in 1934 in Budapest, Hungary. He attended the Technical University of Budapest from 1953 to 1956, majoring in electrical engineering. After participating in the 1956 anti-Soviet revolution, he escaped and immigrated to the United States. He finished his undergraduate work at the Illinois Institute of Technology (1958), followed by MS (1959) and Ph.D (1962) degrees from Northwestern University. He was one of the first doctoral students to specialize in biomedical engineering (adviser R.W. Jones) under the aegis of the Electrical Engineering department. His thesis work on modeling predictive eye movements is still being cited... [1] Upon completing his degree, he accepted a position with Raymond Carhart in Audiology at Northwestern and became a full professor seven years later. His entire faculty career, which spanned fifty years, was at Northwestern University. In 1977-78 he spent a sabbatical year at the Karolinska Institutet, Stockholm, Sweden, working with Åke Flock. In 1991 he was recruited to be the founding chair of the new Department of Neurobiology and Physiology. Later he served terms as Associate Dean in the College of Arts and Sciences and as Vice President for Research. He was the founding Editor-in-Chief of the journal Auditory Neuroscience (1994–97), served on the Council of Neurology Institute of the NIH (1984–87) and was President of the Association for Research in Otolaryngology (ARO; 1992–93), while also serving on numerous other advisory committees and boards and holding various editorships.

Research

Early work pertained to elucidating the properties and modeling of the acoustic reflex and some excursions into psychophysics. By 1965 he established the Auditory Physiology Laboratory where he and some seventy doctoral students, postdocs and colleagues have produced a body of work that can be characterized in various categories.

[2.1] Contemporary interpretation of the origin and properties of gross electrical responses of the cochlea and auditory nerve. This work forms the basis of present-day measurements and understanding of compound electrical responses of the auditory periphery. The work was summarized in the 1973 monograph: The Auditory Periphery. [2]

[2.2] Discovery of fractional subharmonics in cochlear mechanics, including the first report on chaotic behavior in a biological system, as well as the first demonstration of a form of otoacoustic emissions. [3]

[2.3] First physiological demonstration that cochlear distortion is related to hair cell transduction . [4]

[2.4] First explanation of what determines low-frequency auditory threshold [5]

[2.5] Discovery that inner hair cells respond to basilar membrane velocity [6]

[2.6] Demonstration that in the absence of outer hair cells there is a significant threshold shift, change in frequency selectivity, and linearization of the cochlea. This experimental series forms the basis of much of our current concepts of cochlear function, notably 50-60 dB amplification by outer hair cells [7] [8] [9]

[2.7] First intracellular recordings from outer hair cells in vivo; first intracellular recordings from hair cells in the low-frequency regions of the cochlea [10] [11] [12]

[2.8] First recordings from auditory nerve terminals in vivo [13]

[2.9] Experimental series establishing many properties of electromotility of isolated outer hair cells, including the proof that stereocilia displacement produces outer hair cell motility [14] [15] [16] [17] [18] [19]

[2.10] Invention and development of the hemicochlea technique and intracellular recordings from hair cells in the hemicochlea under basilar membrane stimulation [20] [21] [22]

[2.11] Discovery that outer hair cell axial stiffness is voltage dependent [23]

[2.12] Discovery and elucidation of the properties of the unique outer hair cell motor protein, prestin (SLC26A5), and studies of cochlear amplification in prestin knockin and knockout mice, proof that prestin-driven outer hair cell motility is the mammalian cochlear amplifier [24] [25] [26] [27] [28] [29]

[2.13] Numerous highly cited review articles [30] [31]

[2.14] Books edited [32] [33] [34]

Selected awards

Sculpting

He has been making welded steel sculptures since 1998 and has been a professional sculptor since his retirement from his professorship in 2012. Has had solo shows in Chicago and New York commercial galleries and participated in numerous juried group shows. Had a solo show at the Weisman Museum of Art, Minneapolis and had his work in small-group shows at the Ukrainian Museum of Art, Chicago and the Hamilton Gallery of Montreat College, NC. His War Series of nine sculptures are in the permanent collection of the US Memorial Holocaust Museum, Washington, DC.

Related Research Articles

Inner ear innermost part of the vertebrate ear

The inner ear is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:

Cochlea organ of the inner ear

The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory organ of hearing, which is distributed along the partition separating fluid chambers in the coiled tapered tube of the cochlea.

Basilar membrane

The basilar membrane is a stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani. The basilar membrane moves up and down in response to incoming sound waves, which are converted to traveling waves on the basilar membrane.

Organ of Corti type of mechanoreceptor

The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses' action potential. Transduction occurs through vibrations of structures in the inner ear causing displacement of cochlear fluid and movement of hair cells at the organ of Corti to produce electrochemical signals.

Auditory system particularly in the context of auditory processing disorder

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Hair cell auditory nerve cells

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In physiology, tonotopy is the spatial arrangement of where sounds of different frequency are processed in the brain. Tones close to each other in terms of frequency are represented in topologically neighbouring regions in the brain. Tonotopic maps are a particular case of topographic organization, similar to retinotopy in the visual system.

Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult.

In audiology and psychoacoustics the concept of critical bands, introduced by Harvey Fletcher in 1933 and refined in 1940, describes the frequency bandwidth of the "auditory filter" created by the cochlea, the sense organ of hearing within the inner ear. Roughly, the critical band is the band of audio frequencies within which a second tone will interfere with the perception of the first tone by auditory masking.

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Tectorial membrane membrane in the cochlea of the inner ear

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Hearing Sensory perception of sound by living organisms

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The cochlear amplifier is a positive feedback mechanism within the cochlea that provides acute sensitivity in the mammalian auditory system. The main component of the cochlear amplifier is the outer hair cell (OHC) which increases the amplitude and frequency selectivity of sound vibrations using electromechanical feedback.

The neuronal encoding of sound is the representation of auditory sensation and perception in the nervous system.

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Spatial hearing loss, refers to a form of deafness that is an inability to use spatial cues about where a sound originates from in space. This in turn affects the ability to understand speech in the presence of background noise.

Electrocochleography is a technique of recording electrical potentials generated in the inner ear and auditory nerve in response to sound stimulation, using an electrode placed in the ear canal or tympanic membrane. The test is performed by an otologist or audiologist with specialized training, and is used for detection of elevated inner ear pressure or for the testing and monitoring of inner ear and auditory nerve function during surgery.

Cochlea is Latin for “snail, shell or screw” and originates from the Greek word κοχλίας kokhlias. The modern definition, the auditory portion of the inner ear, originated in the late 17th century. Within the mammalian cochlea exists the organ of Corti, which contains hair cells that are responsible for translating the vibrations it receives from surrounding fluid-filled ducts into electrical impulses that are sent to the brain to process sound.

A. James Hudspeth American university teacher

A. James Hudspeth is the F.M. Kirby Professor at Rockefeller University, where he is director of the F.M. Kirby Center for Sensory Neuroscience. His laboratory studies the physiological basis of hearing.

References

  1. ↑ Dallos, P.J. and R.W. Jones, Learning behavior of the eye fixation control system, IEEE TRANS.AUTO.CONTR. 8: 218-227 (1963).
  2. ↑ Dallos, P. The Auditory Periphery. Biophysics and Physiology (Academic Press, New York, 1973, 566 pages).
  3. ↑ Dallos, P.J., On the generation of odd-fractional subharmonics, J.Acoust.Soc.Amer. 40: 1381-1391 (1966)
  4. ↑ Dallos, P., Z.G. Schoeny, D.W. Worthington and M.A. Cheatham, Cochlear distortion: Effect of direct-current polarization, Science 164: 449-451 (1969)
  5. ↑ Dallos, P., Low-frequency auditory characteristics: Species dependence, J.Acoust.Soc.Amer. 48: 389-399 (1970)
  6. ↑ Dallos, P., M.C. Billone, J.D. Durrant, C.-y. Wang and S. Raynor, Cochlear inner and outer hair cells: Functional differences, Science 177: 356-358 (1972)
  7. ↑ Dallos, P. and C.-y. Wang, Bioelectric correlates of kanamycin intoxication, Audiology 12: 277-289 (1974)
  8. ↑ Ryan, A. and P. Dallos, Absence of cochlear outer hair cells: Effect on behavioural auditory threshold, Nature 253: 44-46 (1975)
  9. ↑ Dallos, P. and D. Harris, Properties of auditory nerve responses in the absence of outer hair cells, J.Neurophysiol. 41: 365-383 (1978)
  10. ↑ Dallos, P., J. Santos-Sacchi and Å. Flock, Cochlear outer hair cells: Intracellular recordings, Science 218: 582-585 (1982).
  11. ↑ Dallos, P., Response characteristics of mammalian cochlear hair cells, J.Neuroscience, 5: 1591-1608 (1985).
  12. ↑ Dallos, P., Neurobiology of cochlear inner and outer hair cells: Intracellular recordings. Hearing Res., 22: 185-198 (1986).
  13. ↑ Siegel, J. and P. Dallos, Spike activity recorded from the organ of Corti. Hearing Res., 22: 245-248 (1986).
  14. ↑ Dallos, P., B.N. Evans and R. Hallworth, Nature of the motor element in electrokinetic shape changes of cochlear outer hair cells. Nature 350: 155-157 (1991).
  15. ↑ Dallos, P., R. Hallworth and B.N. Evans, Theory of electrically-driven shape changes of cochlear outer hair cells, J. Neurophysiol. 70: 299-323 (1993).
  16. ↑ Hallworth, R., B.N. Evans and P. Dallos, The location and mechanism of electromotility in guinea pig outer hair cells, J. Neurophysiol. 70: 549-558 (1993).
  17. ↑ Evans, B.N. and P. Dallos, Stereocilia displacement induced somatic motility of cochlear outer hair cells, Proc.Natl.Acad.Sci.USA 90: 8347-8351 (1993).
  18. ↑ Dallos, P. and B.N. Evans, High frequency motility of outer hair cells and the cochlear amplifier, Science, 267: 2006-2009 (1995).
  19. ↑ Dallos, P., D.Z.Z. He, I. Sziklai, X. Lin, S. Mehta and B.N. Evans, Acetylcholine, outer hair cell electromotility, and the cochlear amplifier, J. Neurosci. 15: 2212-2226 (1997).
  20. ↑ Richter, C.-P., B.N. Evans, R. Edge and P. Dallos, Basilar membrane vibrations in the gerbil hemicochlea, J. Neurophysiol. 79,2255-2264 (1998).
  21. ↑ He, D.Z.Z., S. Jia, P. Dallos, Mechanoelectrical transduction of adult outer hair cells studied in the hemicochlea. Nature 429: 766-770 (2004).
  22. ↑ Jia, S., P. Dallos, D.Z.Z. He, Mechanoelectric transduction of adult inner hair cells, J. Neurosci. 27: 1006-1014 (2007).
  23. ↑ He, D.Z.Z. and P. Dallos, Somatic stiffness of cochlear outer hair cells is voltage dependent, Proc. Natl. Acad. Sci. USA 96, 8223-8228 (1999).
  24. ↑ Zheng, J., W. Shen, D.Z.Z. He, K. Long, L.D. Madison and P. Dallos, Prestin is the motor protein of cochlear outer hair cells, Nature 405, 149-155 (2000).
  25. ↑ Zheng, J., K. B. Long, K. Matsuda, L. D. Madison, A. Ryan and P. Dallos, Genomic characterization and expression of mouse prestin, the motor protein of outer hair cells, Mammalian Genome, 14: 87-96 (2003).
  26. ↑ Cheatham, M.A., K.H. Huynh, J. Gao, J. Zuo, P. Dallos, Cochlear function in Prestin knockout mice. J. Physiol. (London) 569.1: 229-241 (2005).
  27. ↑ Dallos, P. X. Wu, M.A. Cheatham, J. Gao, J. Zheng, C.T. Anderson, S. Jia, W.H.Y. Cheng, D.Z.Z. He and J. Zuo, Prestin-based outer hair cell motility is necessary for mammalian cochlear amplification. Neuron 58: 333-339 (2008).
  28. ↑ Homma, K. and Dallos, P. Dissecting the electromechanical coupling mechanism of the motor-protein prestin. Commun. & Integrative Biol. 4, 450-453. (2011).
  29. ↑ Homma, K., Duan, C., Zheng, J. Cheatham, M.A. and Dallos, P. The V499G/Y501H mutation impairs prestin's fast motor kinetics and has significance for defining functional independence of individual prestin subunits. J. Biol. Chem. 288, 2452-2463 (2013).
  30. ↑ Dallos, P., The active cochlea, J. Neurosci., Invited Feature Article, 12: 4575-4585 (1992).
  31. ↑ Dallos, P. Cochlear amplification, outer hair cells and prestin. Cur. Opin. in Neurobiol. 18: 370-376 (2008).
  32. ↑ Dallos, P., C.D. Geisler, J.W. Matthews, M.A. Ruggero and C.R. Steele, Edts. Mechanics and Biophysics of Hearing (Springer-Verlag, New York, 1990, 418 pages).
  33. ↑ Dallos, P., A. Popper and R. Fay, Edts. The Cochlea Volume 8 in: Springer Handbook of Auditory Research, series editors A. Popper and R. Fay (Springer-Verlag, New York, 1996, 551 pages).
  34. ↑ Dallos, P. and D. Oertel, Edts. Hearing, in the series The Senses: A Comprehensive Reference (Elsevier, London, 2007, 970 pages).
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