An Immunohistochemical Tracing on the Central Neural Pathways An Immunohistochemical Tracing on the Central Neural Pathways / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: The transsynaptic transfer of neurotropic viruses is an effective tool for tracing chains of connected neurons, because replication of virus in the recipient neurons after the transfer amplifies the "tracer signal". The aim of this study is to identify the central neural pathways projecting to the facial nerve using the Bartha strain of the Pseudorabies virus (PRV-Ba )as a transsynaptic tracer. MATERIALS AND METHODS: PRV-Ba was injected into the facial nerve in the stylomastoid foramen of a rat, and was localized in the rat brain with light microscopic immunohistochemistry using primary antibodies against the PRV-Ba. Sequential tracing was carried out on the retrogradely labeled neurons were done. RESULTS: The shapes of upper motor neurons of facial nerve were mostly ovoid or polygonal. The positive immunoreactive cells observed in the brainstem nuclei included raphe obscurus nucleus, facial nucleus, parvocellular reticular nucleus, spinal trigeminal nucleus, ventral parabrachial nucleus, central gray, and dorsal raphe nucleus. Other positive cells stained in the diencephalon were found in periventricular hypothalamic nucleus, dorsal hypothalamic area, orbital gyri, and infralimbic cortex in the frontal lobe. CONCLUSIONS: These results show the central neural pathways of facial nerve using PRV-Ba.