Rights Springer-Verlag REGULAR ARTICLE Development and organization of polarity-specific segregation of primary vestibular afferent fibers in mice

Abstract A striking feature of vestibular hair cells is the polarized arrangement of their stereocilia as the basis for their directional sensitivity. In mammals, each of the vestibular end organs is characterized by a distinct distribution of these polarized cells. We utilized the technique of post-fixation transganglionic neuronal tracing with fluorescent lipid soluble dyes in embryonic and postnatal mice to investigate whether these polarity char-acteristics correlate with the pattern of connections between the endorgans and their central targets; the vestibular nuclei and cerebellum. We found that the cerebellar and brainstem projections develop independently from each other and have a non-overlapping distribution of neurons and affer-ents from E11.5 on. In addition, we show that the vestibular fibers projecting to the cerebellum originate preferentially fro