Neurons in the area postrema are the only catecholamine-synthesizing cells in the medulla or pons with projections to the rostral ventrolateral medulla (C1-area) in the rabbit.
We have identified, in the rabbit medulla and pons, neurons which project to the C1-region of the rostral ventrolateral medulla. By combining tyrosine hydroxylase immunohistochemistry with retrograde transport of Fluoro-Gold we determined whether any of the retrogradely labelled neurons synthesize catecholamines. The only doubly labelled cells were located in the area postrema. No other group of catecholamine-synthesizing neurons in either the medulla or the pons was found to project to the C1-area of the rostral ventrolateral medulla. Pharmacological agents which lower arterial pressure by stimulating adrenoceptors in the rostral ventrolateral medulla may act on receptors which are not innervated by catecholamine-synthesizing perikarya located outside the C1-region.
D000818:Animals; D002395:Catecholamines / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D006651:Histocytochemistry; D008297:Male; D008526:Medulla Oblongata / Q000033:anatomy & histology* / Q000166:cytology / Q000201:enzymology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000166:cytology; D011149:Pons / Q000033:anatomy & histology* / Q000166:cytology / Q000201:enzymology; D011817:Rabbits; D013266:Stilbamidines; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D002395:Catecholamines; D005456:Fluorescent Dyes; D013266:Stilbamidines; D014446:Tyrosine 3-Monooxygenase