Journal article
Distribution of BDNF and trkB mRNA in the otic region of 3.5 and 4.5 day chick embryos as revealed with a combination of in situ hybridization and tract tracing
The International journal of developmental biology, Vol.41(5), pp.725-732
10/1997
PMID: 9415492
Abstract
We have used a recently developed technique which combines fluorescent tract tracing and in situ hybridization to study co-localization of neurotrophin mRNA and neurotrophin receptor mRNA expression simultaneously with the pattern of innervation in the developing chick ear. Efferent and afferent fibersfrom the VII/VIIIth cranial nerves were retrogradely and anterogradely filled with Dextran amines conjugated to Texas red and the brain stem was incubated for 2 hours in tissue culture medium. The tissue was subsequently fixed, sectioned frozen, mounted and subjected to in situ hybridization analysis using probes for brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor, trkB. The results show that afferent and efferent fibers to the ear innervate areas of the developing otocyst which express BDNF mRNA. We also found that neurons in the stato-acoustic ganglion express high levels of trkB mRNA whereas the subset of facial motor neurons that is efferent to the ear only had no or very low levels of trkB mRNA. From our results we conclude that chicken otic efferent fibers preferentially project to areas with BDNF mRNA expression. The very low levels of trkB mRNA in these motor neurons compared to afferent neurons innervating the same region suggest that other factors, perhaps co-expressed with BDNF, may support efferents. A possible involvement of afferents in guiding efferents to specific areas of the ear is suggested.
Details
- Title: Subtitle
- Distribution of BDNF and trkB mRNA in the otic region of 3.5 and 4.5 day chick embryos as revealed with a combination of in situ hybridization and tract tracing
- Creators
- F Hallböök - Uppsala University, Department of Developmental Neuroscience, Sweden. Finn.Hallbook@mun.uu.seB Fritzsch - University of Iowa, Biology
- Resource Type
- Journal article
- Publication Details
- The International journal of developmental biology, Vol.41(5), pp.725-732
- PMID
- 9415492
- NLM abbreviation
- Int J Dev Biol
- ISSN
- 0214-6282
- Grant note
- P 50 DC 00215 / NIDCD NIH HHS
- Language
- English
- Date published
- 10/1997
- Academic Unit
- Iowa Neuroscience Institute; Biology; Craniofacial Anomalies Research Center
- Record Identifier
- 9984071683802771
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