The long-term objective of this research is to shed light on how the cochlea analyzes sound. Others have demonstrated that single outer hair cells isolated in vitro change their longitudinal lengths in response to chemical or electrical stimuli. These and other data suggest that the outer hair cells play a role in the high sensitivity transduction process of the cochlea in response to sound and this has been included in several models. Our goal is to determine how chemicals such as neurotransmitters, modulators, and other chemicals present in the cochlea interact with the outer hair cells and alter their role in the transduction process. The hypothesis to be tested is that chemicals proposed as efferent neurotransmitters and neuromodulators and other chemicals in the cochlea react with receptors on the outer hair cells to produce one or more of the following changes in the outer hair cells: 1) length, and/or 2) ion channel activity, and/or 3) guanine nucleotide binding (G) protein activity. We will examine the mechanisms of any changes found by testing antagonists in addition to monitoring the effects of the chemicals on ion channel activity in the isolated hair cells. This information should aid researchers and physicians in identifying disease states which might involve malfunction of the outer hair cells in the processing of found and in proposing drug intervention therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
2R01DC000722-04
Application #
2125952
Study Section
Hearing Research Study Section (HAR)
Project Start
1991-02-01
Project End
1998-03-31
Budget Start
1994-04-01
Budget End
1995-03-31
Support Year
4
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Louisiana State University Hsc New Orleans
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
782627814
City
New Orleans
State
LA
Country
United States
Zip Code
70112
Ruel, J; Bobbin, R P; Vidal, D et al. (2000) The selective AMPA receptor antagonist GYKI 53784 blocks action potential generation and excitotoxicity in the guinea pig cochlea. Neuropharmacology 39:1959-73
Ruel, J; Chen, C; Pujol, R et al. (1999) AMPA-preferring glutamate receptors in cochlear physiology of adult guinea-pig. J Physiol 518 ( Pt 3):667-80
Nenov, A P; Chen, C; Bobbin, R P (1998) Outward rectifying potassium currents are the dominant voltage activated currents present in Deiters' cells. Hear Res 123:168-82
Parker, M S; Larroque, M L; Campbell, J M et al. (1998) Novel variant of the P2X2 ATP receptor from the guinea pig organ of Corti. Hear Res 121:62-70
Chen, C; Skellett, R A; Fallon, M et al. (1998) Additional pharmacological evidence that endogenous ATP modulates cochlear mechanics. Hear Res 118:47-61
Skellett, R A; Cullen Jr, J K; Fallon, M et al. (1998) Conditioning the auditory system with continuous vs. interrupted noise of equal acoustic energy: is either exposure more protective? Hear Res 116:21-32
Chen, C; Bobbin, R P (1998) P2X receptors in cochlear Deiters' cells. Br J Pharmacol 124:337-44
Nenov, A P; Skellett, R A; Fallon, M et al. (1997) Nitrosoglutathione suppresses cochlear potentials and DPOAEs but not outer hair cell currents or voltage-dependent capacitance. Hear Res 110:77-86
Skellett, R A; Chen, C; Fallon, M et al. (1997) Pharmacological evidence that endogenous ATP modulates cochlear mechanics. Hear Res 111:42-54
Nenov, A P; Norris, C; Bobbin, R P (1997) Outwardly rectifying currents in guinea pig outer hair cells. Hear Res 105:146-58

Showing the most recent 10 out of 35 publications