Linked Life Data

16080998

Source:http://linkedlifedata.com/resource/pubmed/id/16080998

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2005-8-5
pubmed:abstractText
We review the in vivo evidence for afferent fiber guidance to the inner ear sensory epithelia and the central nuclei of termination. Specifically, we highlight our current molecular understanding for the role of hair cells and sensory epithelia in guiding afferents, how disruption of certain signals can alter fiber pathways, even in the presence of normal hair cells, and what role neurotrophins play in fiber guidance of sensory neurons to hair cells. The data suggest that the neurotrophin BDNF is the most important molecule known for inner ear afferent fiber guidance to hair cells in vivo. This suggestion is based on experiments on Ntf3 transgenic mice expressing BDNF under Ntf3 promoter that show deviations of fiber growth in the ear to areas that express BDNF but have no hair cells. However, fiber growth can occur in the absence of BDNF as demonstrated by double mutants for BDNF and Bax. We directly tested the significance of hair cells or sensory epithelia for fiber guidance in mutants that lose hair cells (Pou4f3) or do not form a posterior crista (Fgf10). While these data emphasize the role played by BDNF, normally released from hair cells, there is some limited capacity for directed growth even in the absence of hair cells, BDNF, or sensory epithelia. This directed growth may rely on semaphorins or other matrix proteins because targeted ablation of the sema3 docking site on the sema receptor Npn1 results in targeting errors of fibers even in the presence of hair cells and BDNF. Overall, our data support the notion that targeting of the afferent processes in the ear is molecularly distinct from targeting processes in the central nuclei. This conclusion is derived from data that show no recognizable central projection deviation, even if fibers are massively rerouted in the periphery, as in Ntf3(tgBDNF) mice in which vestibular fibers project to the cochlea.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0378-5955
pubmed:author
pubmed:issnType
Print
pubmed:volume
206
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
52-63
pubmed:dateRevised
2010-9-29
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Mutant mice reveal the molecular and cellular basis for specific sensory connections to inner ear epithelia and primary nuclei of the brain.
pubmed:affiliation
Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, United States. fritzsch@creighton.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Review, Research Support, N.I.H., Extramural