Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction, and reports on seven research projects.National Institutes of Health Grant 5 R01 DC00194National Institutes of Health Grant P01 DC00119National Institutes of Health Grant F32 DC00073National Institutes of Health Grant 5 R01 DC00473National Institutes of Health Grant 2 R01 DC00238National Institutes of Health Grant 2 R01 DC00235National Institutes of Health Grant 5 P01 DC00361National Institutes of Health Grant T32 DC00006Whitaker Health Sciences Fun

Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction and reports on six research projects.National Institutes of Health Grant R01-DC-00194-11National Institutes of Health Grant P01-DC00119 Sub-Project 1National Institutes of Health Grant F32-DC00073-2National Institutes of Health Contract P01-DC00119National Institutes of Health Grant R01-DC00238National Institutes of Health Gramt R01-DC00473National Institutes of Health Grant P01-DC00119National Institutes of Health Grant T32-DC00038PNational Institutes of Health Grant P01-DC00361National Institutes of Health Grant 2RO1 DC00235National Institutes of Health Contract NO1-DC2-240

Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction and reports on six research projects.National Institutes of Health Grant R01-DC-00194National Institutes of Health Contract P01-DC-00119National Institutes of Health Fellowship F32-DC00073National Institutes of Health Grant R01-DC00238National Institutes of Health Grant R01-DC00473National Institutes of Health Grant T32-DC00006National Institutes of Health Grant T32-DC00038National Institutes of Health Contract P01-DC00361National Institutes of Health Grant R01-DC00235National Institutes of Health Contract N01-DC2240

Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction and reports on five research projects.National Institutes of Health Grant R01-DC-00194National Institutes of Health Grant P01-DC-00119Charles S. Draper Laboratory Contract DL-H-496015National Institutes of Health Grant R01 DC00238National Institutes of Health Grant R01-DC02258National Institutes of Health Grant T32-DC00038National Institutes of Health Grant RO1 DC00235National Institutes of Health Grant P01-DC00361National Institutes of Health Contract N01-DC-6-210

Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction and reports on six research projects.National Institutes of Health Grant RO1-DC-00194-11National Institutes of Health Grant PO1-DC00119 Sub-Project 1National Institutes of Health Grant F32-DC00073-3National Institutes of Health Contract P01-DC00119National Institutes of Health Grant R01 DC00238National Institutes of Health Grant P01-DC00119National Institutes of Health Grant T32-DC00038National Institutes of Health Contract P01-DC00361National Institutes of Health Grant R01-DC00235National Institutes of Health Contract NO1-DC2240

Signal Transmission in the Auditory System

Contains table of contents for Section 3, an introduction and reports on seven research projects.National Institutes of Health Grant P01-DC-00119National Institutes of Health Grant R01-DC-00194National Institutes of Health Grant R01 DC00238National Institutes of Health Grant R01-DC02258National Institutes of Health Grant T32-DC00038National Institutes of Health Grant P01-DC00361National Institutes of Health Grant 2RO1 DC00235National Institutes of Health Contract N01-DC2240

Electrophysiological measurements of peripheral vestibular function—A review of electrovestibulography

Electrocochleography (EcochG), incorporating the Cochlear Microphonic (CM), the Summating Potential (SP), and the cochlear Compound Action Potential (CAP), has been used to study cochlear function in humans and experimental animals since the 1930s, providing a simple objective tool to assess both hair cell (HC) and nerve sensitivity. The vestibular equivalent of ECochG, termed here Electrovestibulography (EVestG), incorporates responses of the vestibular HCs and nerve. Few research groups have utilized EVestG to study vestibular function. Arguably, this is because stimulating the cochlea in isolation with sound is a trivial matter, whereas stimulating the vestibular system in isolation requires significantly more technical effort. That is, the vestibular system is sensitive to both high-level sound and bone-conducted vibrations, but so is the cochlea, and gross electrical responses of the inner ear to such stimuli can be difficult to interpret. Fortunately, several simple techniques can be employed to isolate vestibular electrical responses. Here, we review the literature underpinning gross vestibular nerve and HC responses, and we discuss the nomenclature used in this field. We also discuss techniques for recording EVestG in experimental animals and humans and highlight how EVestG is furthering our understanding of the vestibular system

A 3-D Force and Moment Motor for Small-Scale Biomechanics Experiments

The inability to identify 3-D force and moment components for actuators and sensors is a major limiting factor in the study of 3-D force interactions with small-scale biological structures. While recent advances have been made in the measurement of stimulating forces using load cells and atomic-force microscopy in experimental preparations of biological structures such as mammalian temporal bones, these techniques have mostly been limited to one or two dimensions. In this paper, a method is described for stimulating biological structures using a small magnet (2 mg Sm2Co17 ) and a nearby current-conducting coil (46 gauge, 50 turns), that allows the 3-D Lorentz forces and moments acting on the magnet to be calculated. To make these calculations possible, the dimensions and placements of the magnet and coil are accurately determined (within 10 mum for in vitro preparations) using high-resolution micro-CT imaging. This noncontact force motor method has been used to study the mechanics of the malleus-incus complex in the mammalian middle ear in addition to basilar membrane mechanics and fluid flow inside the cochlea, and it can also be applied to the study of other biomechanical structures

Calculation of intertial properties of the malleus-incus complex from micro CT-imaging

The middle ear bones are the smallest bones in the human body and are among the most complicated functionally. These bones are located within the temporal bone making them difficult to access and study. We use the micro-CT imaging modality to obtain quantitative inertial properties of the MIC (malleus-incus complex), which is a subcomponent of the middle ear. The principal moment of inertia of the malleus along the superior-inferior axis (17.3 ± 2.3 mg/mm3) is lower by about a factor of six in comparison to the anterior-posterior and lateral-medial axes. For the incus, the principal moment of inertia along the superior-inferior axis (35.3 ± 6.9 mg/mm3) is lower by about a factor of two than for the other two axes. With the two bones combined (MIC), the minimum principal moment of inertia (132.5 ± 18.5 mg/mm3) is still along the superior-inferior axis but is higher than for the individual bones. The superior-inferior axis inertia is lower by a factor of 1.3 than along the anterior-posterior axis and is lower by a factor 2 along the lateral-medial axis. Values for inertia of the MIC show significant individual differences in three human ears measured, suggesting that middle ear models should be based on individual anatomy. Imaging by micro-CT scanner is a nondestructive modality that provides three-dimensional volume information about middle ear bones at each stage of manipulation with resolution down to 10μm. In this work extraneous tissue is removed to obtain a sufficiently small specimen. However, advances in imaging hold promise that this capability will be available for in vivo measurements