Afferent nerve ending development and synaptogenesis in the vestibular epithelium of human fetuses.

Synaptogenesis has been investigated in the vestibular epithelium of human fetuses aged from 7 to 14 weeks of gestation. The arrival of afferent nerve endings in the epithelium preceded hair cell differentiation. Synaptogenesis involved the proliferation of synaptic bodies. It was concomitant with the formation of contacts between microtubules and the presynaptic membrane, and the presence of numerous coated vesicles within the presynaptic area.