dc.contributor.author |
Telang, Ravindra |
en |
dc.contributor.author |
Paramananthasivam, Vinthiya |
en |
dc.contributor.author |
Vlajkovic, Srdjan |
en |
dc.contributor.author |
Munoz Pabon, David |
en |
dc.contributor.author |
Housley, GD |
en |
dc.contributor.author |
Thorne, Peter |
en |
dc.date.accessioned |
2012-02-26T20:38:16Z |
en |
dc.date.issued |
2010-06 |
en |
dc.identifier.issn |
1573-9538 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/11974 |
en |
dc.description.abstract |
Extracellular adenosine triphosphate (ATP) has profound effects on the cochlea, including an effect on the regulation of the endocochlear potential (EP). Noise-induced release of ATP into the endolymph activates a shunt conductance mediated by P2X2 receptors in tissues lining the endolymphatic compartment, which reduces the EP and, consequentially, hearing sensitivity. This may be a mechanism of adaptation or protection from high sound levels. As inaction of such a process could contribute to hearing loss, this study examined whether the action of ATP on EP changes with age and noise exposure in the mouse. The EP and the endolymphatic compartment resistance (CoPR) were measured in mice (CBA/CaJ) aged between 3 and 15 months. The EP and CoPR declined slightly with age with an associated small, but significant, reduction in auditory brainstem response thresholds. ATP (100–1,000 μM) microinjected into the endolymphatic compartment caused a dosedependent decline in EP correlated to a similar decrease in CoPR. This was blocked by pyridoxal-phosphate-6-azophenyl- 2′,4′-disulfonate, consistent with a P2X2 receptormediated shunt conductance. There was no substantial difference in the ATP response with age. Noise exposure (octave-band noise 80–100 decibels sound pressure level (dBSPL), 48 h) in young animals induced an upregulation of the P2X2 receptor expression in the organ of Corti and spiral limbus, most noticeably with the 90-dB exposure. This did not occur in the aged animals except following exposure at 90 dBSPL. The EP response to ATP was muted in the noiseexposed aged animals except following the 90-dB exposure. These findings provide some evidence that the adaptive response of the cochlea to noise may be reduced in older animals, and it is speculated that this could increase their susceptibility to noise-induced injury |
en |
dc.language |
EN |
en |
dc.publisher |
SPRINGER |
en |
dc.relation.ispartofseries |
Purinergic Signalling |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.subject |
Ageing |
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dc.subject |
Noise |
en |
dc.subject |
Endocochlear potential |
en |
dc.subject |
Auditory brainstem response |
en |
dc.subject |
CBA/CaJ |
en |
dc.subject |
Immunohistochemistry |
en |
dc.subject |
P2X(2) receptors |
en |
dc.subject |
AGE-RELATED-CHANGES |
en |
dc.subject |
GATED ION CHANNELS |
en |
dc.subject |
NK CELL-ACTIVITY |
en |
dc.subject |
RAT COCHLEA |
en |
dc.subject |
AUDITORY NEUROTRANSMISSION |
en |
dc.subject |
PURINERGIC RECEPTORS |
en |
dc.subject |
NEGATIVE MODULATION |
en |
dc.subject |
SOUND TRANSDUCTION |
en |
dc.subject |
NOISE EXPOSURE |
en |
dc.subject |
ADRENAL-GLAND |
en |
dc.title |
Reduced P2x(2) receptor-mediated regulation of endocochlear potential in the ageing mouse cochlea |
en |
dc.type |
Journal Article |
en |
dc.identifier.doi |
10.1007/s11302-010-9195-6 |
en |
pubs.issue |
2 |
en |
pubs.begin-page |
263 |
en |
pubs.volume |
6 |
en |
dc.rights.holder |
Copyright: SPRINGER |
en |
dc.identifier.pmid |
20806017 |
en |
pubs.end-page |
272 |
en |
pubs.publication-status |
Published |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/RestrictedAccess |
en |
pubs.subtype |
Article |
en |
pubs.elements-id |
120033 |
en |
pubs.org-id |
Medical and Health Sciences |
en |
pubs.org-id |
Medical Sciences |
en |
pubs.org-id |
Physiology Division |
en |
pubs.org-id |
Population Health |
en |
pubs.org-id |
Audiology |
en |
pubs.record-created-at-source-date |
2012-02-27 |
en |
pubs.dimensions-id |
20806017 |
en |