title: Distribution and innervation of putative arterial chemoreceptors in the bullfrog (Rana catesbeiana).
abstract: Peripheral arterial chemoreceptors have been located previously in the carotid labyrinth, the aortic arch, and the pulmocutaneous artery of frogs. In the present study we used cholera toxin B neuronal tract tracing and immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH), and serotonin (5HT) to identify putative O2-sensing cells in Rana catesbeiana. We found potential O2-sensing cells in all three vascular areas innervated by branches of the vagus nerve, whereas only cells in the carotid labyrinth were innervated by the glossopharyngeal nerve. Cells containing either 5HT or TH were found in all three sites, whereas cells containing both neurotransmitters were found only in the carotid labyrinth. Cell bodies containing VAChT were not found at any site. The morphology and innervation of putative O2-sensing cells were similar to those of glomus cells found in other vertebrates. The presence of 5HT- and TH-immunoreactive cells in the aorta, pulmocutaneous artery, and carotid labyrinth appears to reflect a phylogenetic transition between the major neurotransmitter seen in the putative O2-sensing cells of fish (5HT) and those found in the glomus cells of mammals (acetylcholine, adenosine, and catecholamines).
authors: Department of Zoology, University of British Columbia, Vancouver, British Columbia, Vancouver, V6T 1Z4, Canada.
authors: Catalina
authors: C
authors: Reyes
authors: Angelina Y
authors: AY
authors: Fong
authors: Dee L
authors: DL
authors: Brink
authors: William K
authors: WK
authors: Milsom
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology* / Q000648:ultrastructure; D001158:Arteries / Q000166:cytology* / Q000648:ultrastructure; D018959:CD57 Antigens / Q000378:metabolism; D048429:Cell Size; D002628:Chemoreceptor Cells / Q000145:classification / Q000378:metabolism* / Q000648:ultrastructure; D002772:Cholera Toxin / Q000378:metabolism; D007758:Ear, Inner / Q000166:cytology / Q000648:ultrastructure; D005260:Female; D008297:Male; D008855:Microscopy, Electron, Scanning; D011892:Rana catesbeiana / Q000033:anatomy & histology*; D012701:Serotonin / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014630:Vagus Nerve / Q000502:physiology; D050494:Vesicular Acetylcholine Transport Proteins / Q000378:metabolism
chemical_list: D018959:CD57 Antigens; D050494:Vesicular Acetylcholine Transport Proteins; D012701:Serotonin; D002772:Cholera Toxin; D014446:Tyrosine 3-Monooxygenase
keywords: AB_10013220; AB_261875; AB_397184; AB_477522; AB_572262; AB_572268; acetylcholine; catecholamines; chemoreception; frogs; hypoxia; nif-0000-10474; nif-0000-30467; oxygen-sensing cells; serotonin