当前位置： SCI文献检索 > HEARING RESEARCH期刊下所有文献 > Time-varying alterations in the f2-f1 DPOAE response to continuous primary stimulation. I: Response characterization and contribution of the olivocochlear efferents.

Time-varying alterations in the f2-f1 DPOAE response to continuous primary stimulation. I: Response characterization and contribution of the olivocochlear efferents.

Abstract：

:The f2-f1 distortion product otoacoustic emission (DPOAE) can be observed to undergo gradual alterations in amplitude during continuous ipsilateral stimulation with primary tones. In the present experiments, we characterized the dependence of these amplitude alterations on several stimulus variables (intensity, duration, frequency) and on DPOAE type (quadratic vs cubic) and tested the hypothesis that such alterations are mediated by the olivocochlear (OC) efferents. Responses were recorded in urethane-anesthetized guinea pigs with sectioned middle ear muscles before and after intracochlear application of antagonists (curare, 1 microM; bicuculline, 10 microM; tetrodotoxin, 1 microM) or before and after OC efferent section at the midline of the floor of the IVth ventricle. We confirm previous reports of continuous stimulation-related alterations in the amplitude of the quadratic distortion product, f2-f1, and report a novel, suppressive 'off-effect' apparent in f2-f1 amplitude following a short rest from such stimulation. Response alterations were sensitive to primary intensity and to duration of rest from continuous stimulation, but were not clearly frequency-dependent over the ranges tested. Corresponding alterations in the amplitude of the cubic nonlinearity, 2f1-f2 were very small or absent. Amplitude alterations in f2-f1 were reduced but not blocked by OC efferent antagonists (curare, bicuculline) and were largely unaffected by TTX or by midline brainstem section. All of these manipulations, however prevented completely the known efferent-mediated contralateral sound suppression of both f2-f1 and 2f1-f2 DPOAEs. Taken together, these results do not provide support for efferent control of the f2-f1 amplitude alterations observed during continuous ipsilateral stimulation.

journal_name

Hear Res

journal_title

Hearing research

authors

Kujawa SG,Fallon M,Bobbin RP

doi

10.1016/0378-5955(95)00041-2

subject

Has Abstract

pub_date

1995-05-01 00:00:00

pages

142-54

issue

1-2

eissn

0378-5955

issn

1878-5891

pii

0378-5955(95)00041-2

journal_volume

pub_type

杂志文章

在线工具

Time-varying alterations in the f2-f1 DPOAE response to continuous primary stimulation. I: Response characterization and contribution of the olivocochlear efferents.