Study on Catecholaminergic Neurons in Central Pathways Supplying the Vagus Nerve / 대한해부학회지

ABSTRACT

This study aimed to carry out the reconstruction of whole tract of the vagus nerve using new powerful neurotracer which can migrate easily to the neighboring neurons through synapse and identify whether catecholaminergic neurons exist or not in the central vagal pathways. Pesudorabies virus (PRV-Ba) was used as a neurotracer and antibody to the PRV-Ba was used to localize the tracer in neurons immunohistochemically. The PRV-Ba was injected into the cervical portion of the vagus nerve of Sprague-Dawley rats. After 3 to 4 days of survival periods, brain tissues were fixed, sectioned and stained using anti-PRV-Ba and ABC method subsequently. Motor neurons of the vagus nerve were originated exclsively from dorsal motor nucleus of the vagus nerve and nucleus ambiguus in the medulla oblongata which project fiber by way of nucleus tractus solitarius up to the cerebrum including the paraventricular nucleus. Double labelled neurons were found mostly throughout the brainstem. The adrenergic inputs arose from the C1, C2, and C3 cell groups. Noradrenergic inputs originated predominately from A5 cell group, with lesser contributions from A1 and A7 cell groups as well as locus ceruleus. Some weakly stained TH-immunoreac-tive neurons, presumably dopaminergic, were labelled in the paraventicular nucleus. In conclusion, motor neurons projecting to the vagus nerve includes noradrenergic neurons of the brainstem and from a dopaminergic neurons in the paraventicular nucleus.