Distribution and innervation of putative arterial chemoreceptors in the bullfrog (Rana catesbeiana).
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).
['Reyes|Catalina|C|', 'Fong|Angelina Y|AY|', 'Brink|Dee L|DL|', 'Milsom|William K|WK|']
D000818:Animals D001011:Aorta D001158:Arteries D018959:CD57 Antigens D048429:Cell Size D002628:Chemoreceptor Cells D002772:Cholera Toxin D007758:Ear, Inner D005260:Female D008297:Male D008855:Microscopy, Electron, Scanning D011892:Rana catesbeiana D012701:Serotonin D014446:Tyrosine 3-Monooxygenase D014630:Vagus Nerve D050494:Vesicular Acetylcholine Transport Proteins
frogs acetylcholine serotonin catecholamines AB_10013220 AB_261875 AB_397184 AB_477522 AB_572262 AB_572268 chemoreception hypoxia nif-0000-10474 nif-0000-30467 oxygen-sensing cells