Anat Embryol (Berl)
1986;174(3):369-77
Development of the auditory hair
cell surface in human fetuses. A scanning electron microscopy study.
Lavigne-Rebillard M, Pujol R
Thirteen human fetal cochleas were
investigated by scanning electron microscopy. Our observations concentrated
on the hair cell surface. Ciliogenesis appeared to start during the 11th
week of gestation on the inner hair cells (IHCs) and one week later on
the outer hair cells (OHCs). The earliest stages of stereociliary development
were similar on both types of cell and were characterized by the presence
of round bundles of cilia arising from the surrounding microvilli. A three-dimensional
V-shaped arrangement suddenly appeared, accompanied by the disappearance
of short cilia on the internal side. Between the 20th and the 22nd weeks
of gestation, both types of hair cell had an adult stereociliary pattern,
i.e. a rectilinear arrangement on IHCs and W-shaped on OHCs. However,
there were signs of immaturity, such as a disarray of OHCs and the presence
of the kinocilium, suggesting that the surface of the auditory hair cells
achieves its maturation during the last trimester of pregnancy.
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