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 on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC000127-14
Application #
3215786
Study Section
Hearing Research Study Section (HAR)
Project Start
1979-07-01
Project End
1992-06-30
Budget Start
1990-07-01
Budget End
1992-06-30
Support Year
14
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Connecticut
Department
Type
Schools of Dentistry
DUNS #
City
Farmington
State
CT
Country
United States
Zip Code
06030
Leung, Alan W; Kent Morest, D; Li, James Y H (2013) Differential BMP signaling controls formation and differentiation of multipotent preplacodal ectoderm progenitors from human embryonic stem cells. Dev Biol 379:208-20
García-Hernández, Sofía; Potashner, Steven J; Morest, D Kent (2013) Role of fibroblast growth factor 8 in neurite outgrowth from spiral ganglion neurons in vitro. Brain Res 1529:39-45
Feng, J; Bendiske, J; Morest, D K (2012) Degeneration in the ventral cochlear nucleus after severe noise damage in mice. J Neurosci Res 90:831-41
Feng, J; Bendiske, J; Morest, D K (2010) Postnatal development of NT3 and TrkC in mouse ventral cochlear nucleus. J Neurosci Res 88:86-94
Wang, S J; Furusho, M; D'Sa, C et al. (2009) Inactivation of fibroblast growth factor receptor signaling in myelinating glial cells results in significant loss of adult spiral ganglion neurons accompanied by age-related hearing impairment. J Neurosci Res 87:3428-37
Hill, Gerhard W; Morest, D Kent; Parham, Kourosh (2008) Cisplatin-induced ototoxicity: effect of intratympanic dexamethasone injections. Otol Neurotol 29:1005-11
D'Sa, Chrystal; Gross, Julia; Francone, Victor P et al. (2007) Plasticity of synaptic endings in the cochlear nucleus following noise-induced hearing loss is facilitated in the adult FGF2 overexpressor mouse. Eur J Neurosci 26:666-80
Hurd, L B; Hutson, K A; Morest, D K (1999) Cochlear nerve projections to the small cell shell of the cochlear nucleus: the neuroanatomy of extremely thin sensory axons. Synapse 33:83-117
Bilak, S R; Morest, D K (1998) Differential expression of the metabotropic glutamate receptor mGluR1alpha by neurons and axons in the cochlear nucleus: in situ hybridization and immunohistochemistry. Synapse 28:251-70
Josephson, E M; Morest, D k (1998) A quantitative profile of the synapses on the stellate cell body and axon in the cochlear nucleus of the chinchilla. J Neurocytol 27:841-64

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