Acid-sensing ion channel 2 (ASIC2) in the intestine of adult zebrafish.
ABSTRACT Acid-sensing ion channels (ASICs) in mammals monitor acid sensing and mechanoreception. They have a widespread expression in the central and peripheral nervous system, including the gut. The distribution of ASICs in zebrafish is known only in larvae and at the mRNA level. Here we have investigated the expression and cell distribution of ASIC2 in the gut of adult zebrafish using PCR, Western blot and immunohistochemistry. ASIC2 mRNA was detected in the gut, and a protein consistent with predicted ASIC2 (64kDa molecular mass) was detected by Western blot. ASIC2 positivity was found in a subpopulation of myenteric neurons in the enteric nervous system, as well in enteroendocrine epithelial cells. These data demonstrate for the first time the occurrence of ASIC2 in the gut of adult zebrafish where it presumably acts as a chemosensor and a mechanosensor.
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ABSTRACT: Nociception is the sensory mechanism used to detect cues that can harm an organism. The understanding of the neural networks and molecular controls of the reception of pain remains an ongoing challenge for biologists. While we have made significant progress in identifying a number of molecules and pathways that are involved in transduction of noxious stimuli, from the skin through the sensory receptor cell and from this to the spinal cord on into the central nervous system, we still lack a clear understanding of the perceptual processes, the responses to pain and the regulation of pain perception. Mice and rat animal models have been extensively used for nociception studies. However, the study of pain and noiception in these organisms can be rather laborious, costly and time consuming. Conversely the use of Drosophila and C. elegans may be affected by the large evolutionary distance between these animals and humans. We outline here the reasons why zebrafish presents a new and attractive model for studying pain reception and responses and the most interesting findings in the study of nociception that have been obtained using the zebrafish model. © 2013 Wiley Periodicals, Inc.Journal of Cellular Physiology 04/2013; 228(10). DOI:10.1002/jcp.24379 · 3.87 Impact Factor
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ABSTRACT: In detecting chemical properties of food, different molecules and ion channels are involved including members of the acid-sensing ion channels (ASICs) family. Consistently ASICs are present in sensory cells of taste buds of mammals. In the present study the presence of ASICs (ASIC1, ASIC2, ASIC3 and ASIC4) was investigated in the taste buds of adult zebrafish (zASICs) using Westernblot and immunohistochemistry. zASIC1 and zASIC3 were regularly absent from taste buds, whereas faint zASIC2 and robust zASIC4 immunoreactivities were detected in sensory cells. Moreover, zASIC2 also immunolabelled nerves supplying taste buds. The present results demonstrate for the first time the presence of zASICs in taste buds of teleosts, with different patterns to that occurring in mammals, probably due to the function of taste buds in aquatic environment and feeding. Nevertheless, the role of zASICs in taste remains to be demonstrated.Neuroscience Letters 01/2013; DOI:10.1016/j.neulet.2013.01.006 · 2.06 Impact Factor
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ABSTRACT: A role for acid sensing ion channels to serve as epithelial channels for the uptake of Na(+) by the gill of freshwater rainbow trout was investigated. We found that ASIC inhibitors, DAPI and diminazene, decreased Na(+) uptake in adult rainbow trout in a dose-dependent manner, with an IC50 of 0.12 μM and 0.96 μM, respectively. Furthermore, we cloned the trout ASIC1 and ASIC4 homologues and demonstrated that they are expressed differentially in the tissues of the rainbow trout, including gills and isolated mitochondrion-rich cells. Immunohistochemical analysis using custom made anti-zASIC4b antibody and the Na(+)/K(+)- ATPase (α5) antibody demonstrated that the trout ASIC localizes to Na(+)/K(+) - rich cells in the gill. Moreover, 3-D rendering of confocal micrograph demonstrated that ASIC is found in the apical region of mitochondrion- rich cells. We present a revised model, whereby ASIC4 is proposed as one mechanism for Na(+) uptake from dilute freshwater in the gill of rainbow trout.AJP Cell Physiology 06/2014; DOI:10.1152/ajpcell.00398.2013 · 3.71 Impact Factor