The Journal of Neuroscience, May 15, 2002, 22(10):4241-4247
Variation in Inter-Animal Susceptibility to Noise Damage Is
Associated with
9 Acetylcholine Receptor Subunit Expression
Level
Anne E.
Luebke1, 2 and
Paul K.
Foster1
1 Department of Otolaryngology and
2 Neuroscience Program, University of Miami School of
Medicine, Miami, Florida 33136
Large intersubject variabilities in acoustic injury are known to
occur in both humans and animals; however, the mechanisms underlying
such differences are poorly understood. The olivocochlear efferent
system has been hypothesized to play a significant role in protecting
the cochlea from noise overexposure. In this study, we demonstrate that
a newly developed test for determining average efferent system strength
can predict intersubject variations in acoustic injury. In addition,
the intersubject variability in cochlear expression of the
9 subunit
of the nicotinic acetylcholine receptor was found to be proportional to
an animals average efferent strength. Therefore, the inter-animal
variability in the
9-containing acetylcholine receptor expression
may be one mechanism contributing to the inter-animal variability in
acoustic injury.
Key words:
efferent; cochlea; hair cells;
9 subunit of the
nicotinic acetylcholine receptor; distortion-product otoacoustic
emissions; fast-adaptation; noise-induced hearing loss; noise
susceptibility
Copyright © 2002 Society for Neuroscience 0270-6474/02/22104241-07$05.00/0