[Projections of 5-HTergic fibers to the spinal phrenic nucleus and medullary phrenic premotor neurons in the cat].
Experiments were performed on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into the spinal phrenic nucleus. The brainstem sections were double processed for HRP histochemical staining with TMB-DAB method and 5-HT immunohistochemical staining with anti-5-HT primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-5-HT double-labeled neurons were observed mainly in the nucleus raphe pallidus. A few double-labeled neurons were also observed in nucleus raphe obscurus and nucleus raphe magnus. 5-HT immunopositive terminal fibers were observed in the vicinity of HRP single-labeled neurons (phrenic premotor neurons) located in the nucleus ambiguus and ventrolateral solitary tract nucleus. The results indicate that the 5-HTergic neurons in the nucleus raphe pallidus send axonal projections to the phrenic nucleus, and that the brainstem phrenic premotor neurons also receive 5-HTergic axonal projections.
Song
G
G
Department of Physiology, Medical College, Shandong University, Jinan 250012. gangsg@sdu.edu.cn
Li
Q
Q
Shao
F Z
FZ
D000818:Animals; D002415:Cats; D008526:Medulla Oblongata / Q000033:anatomy & histology*; D009046:Motor Neurons; D009412:Nerve Fibers; D011903:Raphe Nuclei / Q000033:anatomy & histology*; D012701:Serotonin / Q000502:physiology*; D013116:Spinal Cord / Q000033:anatomy & histology*
D012701:Serotonin