Formation and maturation of the vestibular ganglion.

The morphologic development of the vestibular ganglia with their peripheral neuronal connections was followed from terminal mitosis until the adult stage (CBA/CBA mouse). Schwann cells enclose vestibular ganglion cells and their peripheral nerve fibres already on the 15th-16th gestational days. The morphological basis for at least some physiological activity is present already before birth. As compared with the spiral ganglion, the vestibular ganglion and its peripheral pathways become mature as much as 5-7 days earlier. An adult morphology is reached during the first postnatal week.