The Journey so Far

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The Journey so Far
How have we arrived at the spot where
Sensorineural hearing loss is still a mystery, a
puzzle largely yet to be solved?
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Diagnostic Visualization Across the Ages
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Manipulation (Rx) of SNHL Across the Ages
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Monitoring of SNHL Across the Ages
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Changing concepts auditory anatomy Physiology

• Labyrinth filled with air from Aristotle till
  1760
• No, Labyrinth completely filled with fluid
  Domenigo Cotugno, 1760
• Low tone perceived _at_ the base of cochlea, high
  tone at the top Duverney, 1683
• Marquis de Corti, described the Organ of Corti in
  an 1851 publication
• Structures of the basilar membrane act as fine
  tuned resonators that excite the attached nerve
  fibres Helmoltz, 1870
• Basilar membrane motion is due to travelling
  waves along it, not due to any resonation of the
  membrane by the sound stimulus Georg Von Bekesy
  (Nobel laureate, 1961) - ???
• Gold, 1948, ffb. Kemp (1978) Ear also emits
  sound
• Hair Cell Motility Brownell, Zenner, Flock, etc

• To be deaf is to be deaf
• -Early Anatomists till 1973
• Concept challenged at the IFOS world congress,
  1973 by
• William House
• Dead Hair cells, being neural
• cells do not regenerate
• - valid until 1987, now neuropeptides
  protective effects
• known (neurotrophins, BDNF, GDNF, FGF, etc)

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2. What is the nature of the neurotransmitter
released Here? Acetycholine? Glutamine?
Schematic representation of structures and
function of the auditory system both efferent and
afferent pathway
1. The OHC demonstrates some electromotility..
What is the nature of the motor protein
responsible for this motility? And how does it
influence the IHC response?
5. Part of the epithelial barrier enclosing
endolymph is the highly-vascularised stria
vascularis, whose cells form tight junctions
responsible for the endocochlear potential (K
influx)
Outer Ear
4. How can we directly visualized and influenced
this level the IHCs and the OHCs?
3. Most of the research
on the cochlear has concentrated here. And are
mostly carried out in rodents, or specimens
obtained from labyrinthectomies.
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What Are the Challenges to Achieving and Closing
These Missing Links?
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Interaction of the Three
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Dendrimers The Molecules of the Future
Visualization
Diagnosis
Diagnosis
Manipulation
Manipulation
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As the focus of science moves from microscopic to
sub-microscopic, and as medicine moves from
tissue/organ treatment to molecular/atomic, the
emerging nanoscience, and its application,
nanotechnology offer a ray of hope for
individuals with sensorineural hearing loss. The
realization of this hope is not far away
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Thank You