Maurice J. Kernan (2007): Mechanotransduction and auditory transduction in
Drosophila. Pflugers Arch. - Eur. J. Physiol., 454 (5), 703?720.
Abstract: Insects are utterly reliant on sensory mechanotransduction, the
process of converting physical stimuli into neuronal receptor potentials.
The senses of proprioception, touch, and hearing are involved in almost
every aspect of an adult insect?s complex behavioral repertoire and are
mediated by a diverse array of specialized sensilla and sensory neurons. The
physiology and morphology of several of these have been described in detail;
genetic approaches in Drosophila, combining behavioral screens and sensory
electrophysiology with forward and reverse genetic techniques, have now
revealed specific proteins involved in their differentiation and operation.
These include three different TRP superfamily ion channels that are required
for transduction in tactile bristles, chordotonal stretch receptors, and
polymodal nociceptors. Transduction also depends on the normal
differentiation and mechanical integrity of the modified cilia that form the
neuronal sensory endings, the accessory structures that transmit stimuli to
them and, in bristles, a specialized receptor lymph and transepithelial
potential. Flies hear near-field sounds with a vibration-sensitive, antennal
chordotonal organ. Biomechanical analyses of wild-type antennae reveal
non-linear, active mechanical properties that increase their sensitivity to
weak stimuli. The effects of mechanosensory and ciliary mutations on
antennal mechanics show that the sensory cilia are the active motor elements
and indicate distinct roles for TRPN and TRPV channels in auditory
transduction and amplification.
URL: http://www.springerlink.com/content/l447r333772v32x5/
For reprints please contact: Maurice J. Kernan (Email:
Lisa Grant and Paul A. Fuchs (2007): Auditory transduction in the mouse.
Pflugers Arch. - Eur. J. Physiol., 454 (5), 793-804.
Abstract: The sensory hair cells of the mammalian cochlea transduce
acoustic stimuli into auditory nerve activity. The biomechanical and
molecular details of hair cell mechanotransduction are being acquired at an
ever-finer level of resolution. In this review, we discuss how selected
mouse mutants and transgenic models have contributed to, and will continue
to shape, our understanding of the molecular basis of hair cell
mechanotransduction. Functional and structural discoveries made originally
in hair cells of nonmammalian vertebrates have been further pursued in the
mouse inner ear, where transgenic manipulation can be applied to test
molecular mechanisms. Additional insights have been obtained from mice
bearing mutations in genes underlying deafness in humans. Taken together,
these studies emphasize the elegance of mechanotransduction, enlarge the
team of molecular players, and begin to reveal the remarkable adaptations
that provide the sensitivity and temporal resolution required for mammalian
hearing.
URL: http://www.springerlink.com/content/w284241462630772/
For reprints please contact: Paul A. Fuchs (Email:
Kind regards,
Sonja
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University of Vienna, Dept. of Behavioural Biology
Sonja Amoser
PhD
Althanstrasse 14
1090 Vienna
Austria
tel: +43 (1) 4277 54467
fax: +43 (1) 4277 54506
mobile: +43 (664) 500 61 06
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