RT Journal Article
T1 Fetal development of the elastic-fiber-mediated enthesis in the human middle ear
A1 Takanashi, Yoshitaka
A1 Shibata, Shunichi
A1 Katori, Yukio
A1 Murakami, Gen
A1 Abe, Shinichi
A1 Rodríguez Vázquez, José Francisco
A1 Kawase, Tetsuaki
AB In the human middle ear, the annular ligament of the incudostapedial joint and the insertions of the tensor tympani and stapedius muscles contain abundant elastic fibers; i.e., the elastic-fiber-mediated entheses. Hyaluronan also coexists with the elastic fibers. In the present study using immunohistochemistry, we demonstrated the distribution of elastin not only in the incudostapedial joint but also in the other two joints of the middle ear in adults and fetuses. In adults, the expression of elastin did not extend out of the annular ligament composed of mature elastic fibers but clearly overlapped with it. Electron microscopic observations of the annular ligament demonstrated a few microfibrils along the elastic fibers. Thus, in contrast to the vocal cord, the middle ear entheses seemed not to contain elaunin and oxytalan fibers. In mid-term fetuses (at approximately 15–16 weeks of gestation) before opening of the external acoustic meatus, the incudostapedial joint showed abundant elastic fibers, but the incudomalleolar and stapediovestibular joints did not. At this stage, hyaluronan was not colocalized, but distributed diffusely in loose mesenchymal tissues surrounding the ear ossicles. Therefore, fetal development of elastin and elastic fibers in the middle ear entheses is unlikely to require acoustic oscillation. In late-stage fetuses (25–30 weeks), whose ear ossicles were almost the same size as those in adults, we observed bundling and branching of elastic fibers. However, hyaluronan expression was not as strong as in adults. Colocalization between elastic fibers and hyaluronan appeared to be a result of postnatal maturation of the entheses.
PB Elsevier
SN 0940-9602
YR 2013
FD 2013-10
LK https://hdl.handle.net/20.500.14352/110616
UL https://hdl.handle.net/20.500.14352/110616
LA eng
NO Yoshitaka Takanashi, Shunichi Shibata, Yukio Katori, Gen Murakami, Shinichi Abe, Jose Francisco Rodríguez-Vázquez, Tetsuaki Kawase, Fetal development of the elastic-fiber-mediated enthesis in the human middle ear, Annals of Anatomy - Anatomischer Anzeiger, Volume 195, Issue 5, 2013, Pages 441-448, ISSN 0940-9602, https://doi.org/10.1016/j.aanat.2013.03.010.
DS Docta Complutense
RD 6 abr 2025