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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-2-6
pubmed:abstractText
A major reorganization of afferent and efferent nerve terminals, concomitant to significant neuronal cell loss and pruning of superfluous fibers, takes place during the development of the organ of Corti, prior to the onset of hearing. We examined the spatio/temporal distribution of subtype-specific AMPA- and N-methyl-d-aspartate (NMDA)-selective glutamate receptor proteins in postnatal inner ears from rats during this critical period. From the first postnatal day onwards, GluR2/3 receptor subtypes appeared in nerve endings of afferent fibers associated with inner and outer hair cells. During the following 2 weeks, GluR2/3 receptors were downregulated in exchange for GluR4 receptors. In parallel efferents projecting from the medial olivocochlear complex to the outer hair cells underwent synaptogenesis and efferents projecting from the lateral olivocochlear complex to the inner hair cells appeared to change contacts to the dendrites of afferents. Concomitant to these events, NMDA receptor subtypes NR1 and NR2A transiently appeared in hair cells as well as afferent and efferent fibers. Recently, we described a temporary expression of the neurotrophin receptor trkB in hair cells, coincident to the growth (GAP-43) and synaptogenesis (synaptophysin) of efferents. Here, we show that trkB was expressed together with NR1 receptors in hair cells in high spatio/temporal correlation with the rearrangement of afferents and efferents. Cochlea NMDA receptors may, therefore, be a part of the mechanism by which, in addition to neurotrophic activity, the mature phenotype of cochlea neurons is acquired through activity-dependent processes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
287
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-41
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Transient expression of NMDA receptors during rearrangement of AMPA-receptor-expressing fibers in the developing inner ear.
pubmed:affiliation
Tübingen Centre for Hearing Research, Laboratory of Biochemistry, Department of Otolaryngology, University of Tübingen, Röntgenweg 11, D-72076 Tübingen, Germany. biochem@mailserv.zdv.uni-tuebingen.de
pubmed:publicationType
Journal Article