ISSN:
1432-119X
Keywords:
Striated muscle Nicotinic acetylcholine receptors Myogenesis Transdifferentiation Neurotrophic factors
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract. TrkB expression was investigated immunocytochemically in the developing musculature of mouse esophagus using conventional and confocal laser scanning microscopy. To demonstrate spatial relationships of TrkB immunoreactive cells to striated and smooth muscle fibers we combined TrkB immunocytochemistry with fluorochrome-tagged α-bungarotoxin for labeling of nicotinic acetylcholine receptors, and α-smooth muscle actin for labeling of smooth muscle cells. At developmental stages E15 to P7, TrkB immunoreactive cells transiently occurred in a transformation zone where striated intermingled with smooth muscle fibers. This transformation zone started in the rostral esophagus at E15, moved caudally, and disappeared between P7 and P10 in the caudal esophagus. The first TrkB-immunoreactive cells appeared in the outer muscle layer at E15. No TrkB-positive cells exhibited acetylcholine receptor clusters or were positive for α-smooth muscle actin. A few showed slight α-bungarotoxin staining over their entire surface. Taken together, the appearance of TrkB-expressing cells in the transformation zone suggest a role in muscle transdifferentiation. Alternatively, these results, together with recent in vitro data, suggest that TrkB is expressed in a subpopulation of myoblasts in which acetylcholine receptor clustering may be inhibited through a TrkB-mediated pathway.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004180000182
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