Document Detail


Human medial olivocochlear reflex: effects as functions of contralateral, ipsilateral, and bilateral elicitor bandwidths.
MedLine Citation:
PMID:  19263165     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Animal studies have led to the view that the acoustic medial olivocochlear (MOC) efferent reflex provides sharply tuned frequency-specific feedback that inhibits cochlear amplification. To determine if MOC activation is indeed narrow band, we measured the MOC effects in humans elicited by 60-dB sound pressure level (SPL) contralateral, ipsilateral, and bilateral noise bands as a function of noise bandwidth from 1/2 to 6.7 octaves. MOC effects were quantified by the change in stimulus frequency otoacoustic emissions from 40 dB SPL probe tones near 0.5, 1, and 4 kHz. In a second experiment, the noise bands were centered 2 octaves below probe frequencies near 1 and 4 kHz. In all cases, the MOC effects increased as elicitor bandwidth increased, with the effect saturating at about 4 octaves. Generally, the MOC effects increased as the probe frequency decreased, opposite expectations based on MOC innervation density in the cochlea. Bilateral-elicitor effects were always the largest. The ratio of ipsilateral/contralateral effects depended on elicitor bandwidth; the ratio was large for narrow-band probe-centered elicitors and approximately unity for wide-band elicitors. In another experiment, the MOC effects from increasing elicitor bandwidths were calculated from measurements of the MOC effects from adjacent half-octave noise bands. The predicted bandwidth function agreed well with the measured bandwidth function for contralateral elicitors, but overestimated it for ipsilateral and bilateral elicitors. Overall, the results indicate that (1) the MOC reflexes integrate excitation from almost the entire cochlear length, (2) as elicitor bandwidth is increased, the excitation from newly stimulated cochlear regions more than overcomes the reduced excitation at frequencies in the center of the elicitor band, and (3) contralateral, ipsilateral, and bilateral elicitors show MOC reflex spatial summation over most of the cochlea, but ipsilateral spatial summation is less additive than contralateral.
Authors:
Watjana Lilaonitkul; John J Guinan
Related Documents :
6699295 - Temporal gap resolution in narrow-band noises with center frequencies from 6000-14000 hz.
2367175 - Critical bands and mixed-frequency scaling: sequential dependencies, equal-loudness con...
17225415 - Binaural comodulation masking release: effects of masker interaural correlation.
21190665 - Efficient light harvesting in a dark, hot, acidic environment: the structure and functi...
7394325 - Effects of intraventricular beta-endorphin and d-ala2-methionine-enkephalinamide on beh...
1769925 - Development of resistance to hearing loss from high frequency noise.
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2009-03-05
Journal Detail:
Title:  Journal of the Association for Research in Otolaryngology : JARO     Volume:  10     ISSN:  1438-7573     ISO Abbreviation:  J. Assoc. Res. Otolaryngol.     Publication Date:  2009 Sep 
Date Detail:
Created Date:  2009-07-29     Completed Date:  2009-10-21     Revised Date:  2011-07-28    
Medline Journal Info:
Nlm Unique ID:  100892857     Medline TA:  J Assoc Res Otolaryngol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  459-70     Citation Subset:  IM    
Affiliation:
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge 02139, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acoustic Stimulation*
Adult
Cochlea / innervation*,  physiology
Cochlear Nerve / physiology*
Ear, Middle / physiology
Female
Humans
Male
Models, Biological
Muscle Contraction / physiology
Olivary Nucleus / physiology
Reflex, Acoustic / physiology*
Grant Support
ID/Acronym/Agency:
P30 DC-05029/DC/NIDCD NIH HHS; R01 DC-005977/DC/NIDCD NIH HHS; R01 DC005977-08/DC/NIDCD NIH HHS
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Transanal endoscopic microsurgery for the treatment of rectal cancer: comparison of wound complicati...
Next Document:  Nestmate and task cues are influenced and encoded differently within ant cuticular hydrocarbon profi...