INTRACELLULAR STUDIES OF THE ORGAN OF CORTI

Project: Research project

Description

The objective of this study is to understand the normal and abnormal
physiology of the sensory cells and neuronal systems in the mammalian
cochlea. The sensory inner and outer hair cells of the organ of Corti are
responsible for receiving acoustic information and transducing the basilar
membrane mechanical motions into a neural code. Knowledge of how cells
functions is essential to other studies which attempt to assess and prevent
hair cell loss; the most common denomination of deafness. Hair cell function, in this study, will be measured using intracellular
recording techniques. The ac and dc receptor potentials, resting membrane
potentials, and sounde-voked cell resistance changes will be recorded for
both outer and inner hair cells. A variety of acouostic stimuli will be
used to stimulate the cells including pure tones, pure tones in acoustic
noise, and two-town combinations. The performance of the hair cells will
be characterized for the changes induced by sound and electrical
stimulation of the efferent nervous system to the cochlea. These efferent
stimulation experiments should help reveal the true purpose of this neural
component to organ of Corti. The endocochlear potential will also be manipulated through the
administration of the diuretic Furosemide and with direct current, in order
to determine if it is required for the high sensitivity and frequency
selectivity of hair cells. The sound varying input resistance of inner
hair cells also will be measured in order to determine if the extracellular
potentials of the cochlea have a role in producing the low-frequency
responses of auditory afferent nerve fibers. Recorded hair cells will be
positively identified by iontophoretic injection of horseradish peroxidase
and subsequent histochemistry and light microscopic inspection of the organ
of Corti surface preparations.
StatusFinished
Effective start/end date4/1/7911/30/89

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health

Fingerprint

Organ of Corti
Outer Auditory Hair Cells
Inner Auditory Hair Cells
Cochlea
Armoracia
Cochlear Nerve
Furosemide
Deafness
Nerve Fibers
Diuretics
Acoustics
Membrane Potentials
Nervous System
Light
Injections

ASJC

  • Medicine(all)
  • Neuroscience(all)