Abstract

application) The main goal of the proposed research is to develop a comprehensive mathematical model of the cochlea mechanics and to use it for the simulation of pathological changes in human hearing related to aging. The project has three specific aims.
Specific Aim 1 is to develop a comprehensive model of passive and active properties of the outer hair cell. The model of outer hair cell will include its passive viscoelastic properties determined by the characteristics of the basic subcellular elements (plasma membrane, cortical lattice, and subsurface cisternae). A nonlinear model of active properties of outer hair cell will be based on observation of its electromotility. Experimental data on viscoelasticity and electromotility of outer hair cell obtained as a result of collaboration with experimental groups of Dr. W.E. Brownell (Baylor College of Medicine) and Dr. R.J. Hallworth (Texas Medical Center) will be used for the outer hair cell model.
Specific Aim 2 is to develop a model of the mechanics of the organ of Corti and integrate it into a model of the intact cochlea. A model of the organ of Corti will include viscoelastic and inertial properties of the basilar membrane, the tectorial membrane, outer hair cell, the stereocilia and their nonlinear interactions. The applicant will use a known approach to the modeling of the intact cochlea with specific terms of the forces acting on the basilar membrane. These terms are determined from their models of outer hair cell and the organ of Corti.
Specific Aim 3 is the modeling of the aging effects. They will use their model for simulation of major pathological factors that have been observed in the aging cochlea; among such factors are the total number of outer hair cells, their distribution along the cochlea, degeneration of the stereocilia, and changes of the outer hair cell properties. They will analyze the effects of these factors by studying the resonant curves of the basilar membrane. The proposed research should provide a fast and accurate interpretation of experimental and clinical data, and may help in developing cochlea implants and effective treatment of the hearing loss in the elderly.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
5K01AG000732-02
Application #
2442197
Study Section
Special Emphasis Panel (ZAG1-BJS-3 (94))
Project Start
1996-08-15
Project End
1999-06-30
Budget Start
1997-08-15
Budget End
1998-06-30
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost

  Institution

Name
Johns Hopkins University
Department
Biomedical Engineering
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218

  Publications

Martomo, Stella A; Saribasak, Huseyin; Yokoi, Masayuki et al. (2008) Reevaluation of the role of DNA polymerase theta in somatic hypermutation of immunoglobulin genes. DNA Repair (Amst) 7:1603-8
Heltemes-Harris, Lynn M; Gearhart, Patricia J; Ghosh, Paritosh et al. (2008) Activation-induced deaminase-mediated class switch recombination is blocked by anti-IgM signaling in a phosphatidylinositol 3-kinase-dependent fashion. Mol Immunol 45:1799-806
Cosentino, S; Scarmeas, N; Helzner, E et al. (2008) APOE epsilon 4 allele predicts faster cognitive decline in mild Alzheimer disease. Neurology 70:1842-9
Alrefai, Rudaina H; Winter, David B; Bohr, Vilhelm A et al. (2007) Nucleotide excision repair in an immunoglobulin variable gene is less efficient than in a housekeeping gene. Mol Immunol 44:2800-5
Cosentino, Stephanie; Scarmeas, Nikolaos; Albert, Steven M et al. (2006) Verbal fluency predicts mortality in Alzheimer disease. Cogn Behav Neurol 19:123-9
Spector, A A (2000) On the mechanoelectrical coupling in the cochlear outer hair cell. J Acoust Soc Am 107:1435-41
Spector, A A; Brownell, W E; Popel, A S (1999) Mechanical and electromotile characteristics of auditory outer hair cells. Med Biol Eng Comput 37:247-51
Spector, A A; Brownell, W E; Popel, A S (1999) Nonlinear active force generation by cochlear outer hair cell. J Acoust Soc Am 105:2414-20
Spector, A A; Brownell, W E; Popel, A S (1998) Elastic properties of the composite outer hair cell wall. Ann Biomed Eng 26:157-65
Spector, A A; Brownell, W E; Popel, A S (1998) Estimation of elastic moduli and bending stiffness of the anisotropic outer hair cell wall. J Acoust Soc Am 103:1007-11

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