Direct projections form catecholaminergic neurons in the caudal ventrolateral medulla to vasopressin-containing neurons in the supraoptic nucleus: a triple-labeling electron microscope study in the rat.
Direct projections form the A1 catecholaminergic cell group in the caudal ventrolateral medulla (CVLM) to arginine-vasopressin-containing (AVP-containing) neurosecretory neurons in the hypothalamic supraoptic nucleus (SON) were examined electron microscopically in the rat by a triple-labeling technique in which an anterograde tract-tracing method of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) was combined with immunocytochemistry for tyrosine hydroxylase (TH) and that for AVP. In the SON, TH-like immunoreactive axon terminals which were labeled with WGA-HRP injected in the CVLM were in synaptic contact with neuronal profiles with AVP-like immunoreactivity. The results indicate that AVP-containing neurons in the SON receive monosynaptic catecholaminergic synaptic input from the CVLM.
Shioda
S
S
Department of Anatomy, Showa University, School of Medicine, Tokyo, Japan. shioda@med.showa-u.ac.jp
Nakai
Y
Y
D000818:Animals; D002395:Catecholamines / Q000032:analysis*; D007150:Immunohistochemistry; D008526:Medulla Oblongata / Q000166:cytology*; D008854:Microscopy, Electron; D009434:Neural Pathways; D009474:Neurons / Q000737:chemistry* / Q000201:enzymology / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000737:chemistry / Q000201:enzymology / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000166:cytology*; D013569:Synapses / Q000737:chemistry / Q000201:enzymology / Q000648:ultrastructure; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis; D014667:Vasopressins / Q000032:analysis*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate
D002395:Catecholamines; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014667:Vasopressins; D014446:Tyrosine 3-Monooxygenase