Date: April 14, 2011
Creator: Wanner, Clinton & Burleson, Mark L.
Description: This paper discusses research on acetylcholine-containing neuroepithelial cells in fish gills. Abstract: The neurochemical link between O2 chemoreceptors and afferent nerves that carry information about O2 levels to cardio-ventilatory centers in the brain has yet to be determined. This study examines the roles of two candidate neurotransmitters thought to be involved in O2 chemoreception, using channel catfish, Ictalurus punctatus. Fish gills are the evolutionary progenitors of arterial arches (aortic and carotid) of mammals where O2 chemoreceptors are located. Neuroepithelial cells (NECs) containing serotonin (5-HT) and acetylcholine (Ach) were confirmed in the first gill arch using immunohistochemistry and laser confocal microscopy. 5-HT-containing NECs were aggregated around the efferent branchial artery, near tips of filaments and lamellae, ACh-containing NECs at the distal tips of filaments. Preliminary co-localization experiments indicate separate 5-HT and Ach-containing cells. This is the first demonstration of ACh-containing NECs and results of this study support pharmacological studies suggesting that ACh is the primary neurochemical involved in O2 chemoreception in vertebrates.
Contributing Partner: UNT Honors College