The processing of interaural level differences (ILDs) is crucial for locating high frequency sounds in the horizontal plane. A wealth of data supports the view that ILDs are computed in the lateral superior olive (LSO) due to an integration of two monaural inputs: an ipsilaterally driven excitation and a contralaterally driven inhibition. However, my recent data show that the medial nucleus of the trapezoid body (MNTB), the source of contralaterally driven inhibition to LSO, is inhibited by sound at the ipsilateral ear. I also find that the inhibition is age-dependent. The goal of this project is to determine the effect of ipsilateral inhibition to MNTB in young and adult animals when acoustically realistic ILDs are presented. A first experiment will study the ILDs that occur in the free field. This will involve recording cochlear microphonics or measuring sound intensity near the tympanic membrane as a sound source is positioned at various azimuthal locations. After obtaining the free field data, I will perform in vivo recordings from the MNTB and measure responses to binaural stimuli whose ILDs correspond to known locations in the horizontal plane. By comparing responses to binaural stimuli with responses to appropriate monaural, contralateral stimuli, the effects of the ipsilateral inhibition will be inferred. I will also investigate the effect of inhibition on spike timing and reliability by examining its effects on phase locking and spike rate variability.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32DC005268-02
Application #
6660662
Study Section
Communication Disorders Review Committee (CDRC)
Program Officer
Sklare, Dan
Project Start
2002-09-01
Project End
Budget Start
2002-09-01
Budget End
2003-08-31
Support Year
2
Fiscal Year
2002
Total Cost
$50,116
Indirect Cost
Name
New York University
Department
Neurology
Type
Schools of Arts and Sciences
DUNS #
004514360
City
New York
State
NY
Country
United States
Zip Code
10012