« Previous AbstractComprehensive study of the organic-solvent-free CDI-mediated acylation of various nucleophiles by mechanochemistry    Next AbstractEffect of VOC loading on the ozone removal efficiency of activated carbon filters »

J Exp Biol

Title:		"Characterisation of chemosensory trigeminal receptors in the rainbow trout, Oncorhynchus mykiss: responses to chemical irritants and carbon dioxide"
Author(s):		Mettam JJ; McCrohan CR; Sneddon LU;
Address:		"University of Liverpool, School of Biological Sciences, Liverpool L69 7ZB, UK"
Journal Title:		J Exp Biol
Year:		2012
Volume:		215
Issue:		Pt 4
Page Number:		685 - 693
DOI:		10.1242/jeb.060350
ISSN/ISBN:		1477-9145 (Electronic) 0022-0949 (Linking)
Abstract:		"Trigeminally innervated, mechanically sensitive chemoreceptors (M) were previously identified in rainbow trout, Oncorhynchus mykiss, but it is not known whether these receptors are responsive only to noxious, chemical irritants or have a general chemosensory function. This study aimed to characterise the stimulus-response properties of these receptors in comparison with polymodal nociceptors (P). Both P and M gave similar response profiles to acetic acid concentrations. The electrophysiological properties were similar between the two different afferent types. To determine whether the receptors have a nociceptive function, a range of chemical stimulants was applied to these receptors, including non-noxious stimuli such as ammonium chloride, bile, sodium bicarbonate and alarm pheromone, and potentially noxious chemical irritants such as acetic acid, carbon dioxide, low pH, citric acid, citric acid phosphate buffer and sodium chloride. Only irritant stimuli evoked a response, confirming their nociceptive function. All receptor afferents tested responded to carbon dioxide (CO(2)) in the form of mineral water or soda water. The majority responded to 1% acetic acid, 2% citric acid, citric acid phosphate buffer (pH 3) and 5.0 mol l(-1) NaCl. CO(2) receptors have been characterised in the orobranchial cavity and gill arches in fish; however, this is the first time that external CO(2) receptors have been identified on the head of a fish. Because the fish skin is in constant contact with the aqueous environment, contaminants with a low pH or hypercapnia may stimulate the nociceptive system in fish"
Keywords:		Acetic Acid/pharmacology Animals Carbon Dioxide/*pharmacology Chemoreceptor Cells/drug effects/*metabolism Electrophysiology Female Irritants/*pharmacology Nociceptors/drug effects/*physiology Oncorhynchus mykiss/*physiology Skin/innervation;
Notes:		"MedlineMettam, Jessica J McCrohan, Catherine R Sneddon, Lynne U eng Research Support, Non-U.S. Gov't England 2012/01/27 J Exp Biol. 2012 Feb 15; 215(Pt 4):685-93. doi: 10.1242/jeb.060350"