ABSTRACT
Though the existence of glutamate-immunoreactive(GL-IR) neurons has been suggested in the nucleus ambiguous(NA) by immunocytochemistry, information regarding the distribution of neurons containing glutamate as a neurotransmitter has been to be elucidated. The author focused on distribution and morphology of GL-IR neurons in the NA, which were compared with cholera toxin beta-subunit(CTB) labeled neurons after its injection to the nodose ganglion(NG) in the cat. The results showed that the majority of neurons in the NA were immunoreactive to excitatory neurotransmitter glutamate, and they seemed to be distributed evenly without any special area of predilection or grouping pattern. The cellular shape was predominantly multipolar. GL-IR neurons showed some similarity in morphology and distribution pattern with CTB labeled cells.