The goal of this research is to discover the structural features of sensory neurons that define their capacities to code information. The emphasis is on the cytological design and pattern of connections of specific types of auditory neurons and their synaptic contracts at the levels of the cochlear nucleus, superior olive, and cochlea. This study relies on the Golgi and classical silver techniques to demonstrate neuronal architecture, silver-degeneration, histochemical, and autoradiographic methods to trace connections and to localize transmitter-related molecules, and electron microscopy applied to normal and experimental material. Sufficient details are obtained to correlate with electrophysiological recordings of sensory neurons, neurochemical studies of transmitter-related molecules, and electron microscopic observations of sensory synapses. The focus for these studies is on a definition of the circuits of specific morphological types of neurons linking inner and outer hair cells with those particular kinds of neurons in the cochlear nucleus which project to those types of neurons in the superior olivary complex forming the olivo-cochlear bundles. The resulting correlations provide a basis for exloring the mechanisms accounting for stimulus coding and information processing in the auditory system. The effects of noise and acoustic deprivation on the structure of central auditory synapses are also being studied.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS014347-10
Application #
3395495
Study Section
Hearing Research Study Section (HAR)
Project Start
1979-07-01
Project End
1991-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
10
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Connecticut
Department
Type
School of Medicine & Dentistry
DUNS #
City
Farmington
State
CT
Country
United States
Zip Code
06030
Ostapoff, E M; Feng, J J; Morest, D K (1994) A physiological and structural study of neuron types in the cochlear nucleus. II. Neuron types and their structural correlation with response properties. J Comp Neurol 346:19-42
Morest, D K; Hutson, K A; Kwok, S (1990) Cytoarchitectonic atlas of the cochlear nucleus of the chinchilla, Chinchilla laniger. J Comp Neurol 300:230-48
Saint Marie, R L; Baker, R A (1990) Neurotransmitter-specific uptake and retrograde transport of [3H]glycine from the inferior colliculus by ipsilateral projections of the superior olivary complex and nuclei of the lateral lemniscus. Brain Res 524:244-53
Ostapoff, E M; Morest, D K; Potashner, S J (1990) Uptake and retrograde transport of [3H]GABA from the cochlear nucleus to the superior olive in the guinea pig. J Chem Neuroanat 3:285-95
Saint Marie, R L; Morest, D K; Brandon, C J (1989) The form and distribution of GABAergic synapses on the principal cell types of the ventral cochlear nucleus of the cat. Hear Res 42:97-112
Saint Marie, R L; Ostapoff, E M; Morest, D K et al. (1989) Glycine-immunoreactive projection of the cat lateral superior olive: possible role in midbrain ear dominance. J Comp Neurol 279:382-96
Ostapoff, E M; Morest, D K (1989) A degenerative disorder of the central auditory system of the gerbil. Hear Res 37:141-62
Winer, J A; Morest, D K; Diamond, I T (1988) A cytoarchitectonic atlas of the medial geniculate body of the opossum, Didelphys virginiana, with a comment on the posterior intralaminar nuclei of the thalamus. J Comp Neurol 274:422-48
Morest, D K; Winer, J A (1986) The comparative anatomy of neurons: homologous neurons in the medial geniculate body of the opossum and the cat. Adv Anat Embryol Cell Biol 97:1-94