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Simonis C, Zink L, Johnston SE, Bogard M, Pyle GG. Effects of water quality on palladium-induced olfactory toxicity and bioaccumulation in rainbow trout (Oncorhynchus mykiss). INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024. [PMID: 38329152 DOI: 10.1002/ieam.4900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/08/2024] [Accepted: 01/19/2024] [Indexed: 02/09/2024]
Abstract
Through emission processes, palladium (Pd) particulates from industrial sources are introduced into a range of ecosystems including freshwater environments. Despite this, research on Pd-induced bioaccumulation, uptake, and toxicity is limited for freshwater fishes. Unlike other metals, there are currently no regulations or protective guidelines to limit Pd release into aquatic systems, indicating a global absence of measures addressing its environmental impact. To assess the olfactory toxicity potential of Pd, the present study aimed to explore Pd accumulation in olfactory tissues, olfactory disruption, and oxidative stress in rainbow trout (Oncorhynchus mykiss) following waterborne Pd exposure. Olfactory sensitivity, measured by electro-olfactography, demonstrated that Pd inhibits multiple pathways of the olfactory system following 96 h of Pd exposure. In this study, the concentrations of Pd for inhibition of olfactory function by 20% (2.5 μg/L; IC20) and 50% (19 μg/L; IC50) were established. Rainbow trout were then exposed to IC20 and IC50 Pd concentrations in combination with varying exposure conditions, as changes in water quality alter the toxicity of metals. Independent to Pd, increased water hardness resulted in decreased olfactory perception owing to ion competition at the olfactory epithelium. No other environmental parameter in this study significantly influenced Pd-induced olfactory toxicity. Membrane-associated Pd was measured at the olfactory rosette and gill following exposure; however, this accumulation did not translate to oxidative stress as measured by the production of malondialdehyde. Our data suggest that Pd is toxic to rainbow trout via waterborne contamination near field-measured levels. This study further demonstrated Pd bioavailability and uptake at water-adjacent tissues, adding to our collective understanding of the toxicological profile of Pd. Taken together, our results provide novel insights into the olfactory toxicity in fish following Pd exposure. Integr Environ Assess Manag 2024;00:1-13. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Carolyn Simonis
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Lauren Zink
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Sarah E Johnston
- Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, Alaska, USA
| | - Matthew Bogard
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
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2
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Frankel TE, Tyler E, Willmore C, Odhiambo BK, Giancarlo L. Assessing the presence, concentration, and impacts of trace element contamination in a Chesapeake Bay tributary adjacent to a coal ash landfill (Possum Point, VA). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 339:122768. [PMID: 37858702 DOI: 10.1016/j.envpol.2023.122768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/11/2023] [Accepted: 10/14/2023] [Indexed: 10/21/2023]
Abstract
Coal ash (CA) is an industrial waste product that has been shown to contain several neurotoxic constituents such as cadmium, selenium, mercury, lead, and arsenic. Contaminant-laced leachates enter the environment via seepage, runoff, permitted discharge, or accidental spills from CA storage ponds or landfills which may pose a risk to wildlife residing in receiving waterways. In this study, we assessed 1) the presence and concentration of thirteen trace elements (Al, Ca, Mg, Cr, Cd, As, Se, Pb, Cu, Zn, Mn, Fe, B) in surface water and sediment grab samples using ICP-OES, 2) the temporal variability of trace elements using Pb-210 dated sediment core samples, 3) differences in species diversity using environmental DNA (eDNA) analyses, and 4) the presence and concentration of trace metals in banded killifish (Fundulus diaphanus) epaxial muscle tissue collected from waterways surrounding the Possum Point Power Station (Stafford, VA). Results showed the highest concentrations of As, Cd, Cr, Cu, Fe, Mg, Se, Zn, and B in Quantico Creek (QC) adjacent to the coal ash ponds and elevated average cadmium and zinc concentrations compared to both upstream and downstream locations along the Potomac River. Sediment core profiles and Pb-210 analyses showed historical enrichment of several trace elements in QC beginning after the commissioning of the power plant in 1948. When compared to upstream and downstream sites, species diversity was drastically reduced in Quantico Creek based on eDNA identification. Muscle tissues of banded killifish collected in Quantico Creek displayed increased Al, Cd, and Zn concentrations compared to upstream and downstream sites. Collectively, our results demonstrate the potential impacts of coal ash landfills on aquatic ecosystems and suggest that further research is needed to fully inform risk assessment and remediation efforts.
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Affiliation(s)
- T E Frankel
- Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Ave, Fredericksburg, VA, 22401, USA.
| | - E Tyler
- Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Ave, Fredericksburg, VA, 22401, USA
| | - C Willmore
- Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Ave, Fredericksburg, VA, 22401, USA
| | - B K Odhiambo
- Department of Earth and Environmental Sciences, University of Mary Washington, 1301 College Ave, Fredericksburg, VA, 22401, USA
| | - L Giancarlo
- Department of Chemistry and Physics, University of Mary Washington, 1301 College Ave, Fredericksburg, VA, 22401, USA
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3
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Fatima R, Briggs R, Dew WA. Avoidance of copper by fathead minnows ( Pimephales promelas) requires an intact olfactory system. PeerJ 2022; 10:e13988. [PMID: 36187749 PMCID: PMC9521343 DOI: 10.7717/peerj.13988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 08/11/2022] [Indexed: 01/19/2023] Open
Abstract
Fish can detect and respond to a wide variety of cations in their environment, including copper. Most often fish will avoid copper during behavioural trials; however, fish may also show no response or an attraction response, depending on the concentration(s) used. While it may seem intuitive that the response to copper requires olfaction, there is little direct evidence to support this, and what evidence there is remains incomplete. In order to test if olfaction is required for avoidance of copper by fathead minnows (Pimephales promelas) copper-induced movement was compared between fish with an intact olfactory system and fish with induced anosmia. Fish in a control group or a mock-anosmic group avoided copper (approximately 10 µg/L or 62.7 nM copper sulphate) while anosmic fish did not. The evidence demonstrates that an intact olfactory system is required for copper sensing in fish.
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Affiliation(s)
- Rubab Fatima
- Biology, Trent University, Peterborough, Ontario, Canada
| | - Robert Briggs
- Biology, Trent University, Peterborough, Ontario, Canada
| | - William A. Dew
- Biology, Trent University, Peterborough, Ontario, Canada,Biology, Algoma University, Sault Ste. Marie, Ontario, Canada
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4
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Lari E, Burket SR, Steinkey D, Brooks BW, Pyle GG. Interaction of the Olfactory System of Rainbow Trout (Oncorhynchus mykiss) with Diltiazem. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:544-550. [PMID: 33463738 DOI: 10.1002/etc.4854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/07/2020] [Indexed: 06/12/2023]
Abstract
Diltiazem is ubiquitously prescribed and has been reported in many effluents and freshwater bodies. Being a calcium channel blocker, diltiazem could disrupt the function of the sensory and central nervous systems. In the present study, using electro-olfactography (EOG), we investigated the interaction of diltiazem with the olfactory sensory neurons (OSNs) of rainbow trout by looking into the detection threshold and effects of immediate (~5 min) and acute (24 h) exposure to diltiazem at 6.6, 66, and 660 µg/L. We also studied the accumulation of the drug in fish plasma and whole body. Brief exposure to diltiazem impaired the OSN response to a chemosensory stimulus in a concentration-dependent manner at 6.6 µg/L and higher, whereas OSNs exposed for 24 h only displayed an impairment at 660 µg/L. Chemical analysis showed that the accumulation of diltiazem in fish plasma and body correlated with the EOG response because it was 10 times higher in the group that displayed a significant impairment (660 µg/L) compared to the other 2 groups (6.6, 66 µg/L). This correlation suggests that the impact of diltiazem on OSNs might partially be through the accumulated molecules in the fish bloodstream. Fish did not detect diltiazem as a sensory stimulus even at concentrations as high as 660 µg/L; thus, fish could potentially swim toward or fail to escape harmful concentrations of diltiazem. Environ Toxicol Chem 2022;41:554-550. © 2020 SETAC.
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Affiliation(s)
- Ebrahim Lari
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - S Rebekah Burket
- Department of Environmental Science, Baylor University, Waco, Texas, USA
| | - Dylan Steinkey
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Bryan W Brooks
- Department of Environmental Science, Baylor University, Waco, Texas, USA
| | - Greg G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
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5
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Assessment of Advanced Oxidation Processes Using Zebrafish in a Non-Forced Exposure System: A Proof of Concept. Processes (Basel) 2021. [DOI: 10.3390/pr9050734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Water bodies and aquatic ecosystems are threatened by discharges of industrial waters. Ecotoxicological effects of components occurring in untreated and treated wastewaters are often not considered. The use of a linear, multi-compartmented, non-forced, static system constructed with PET bottles is proposed for the quality assessment of treated waters, to deal with such limitations. Two synthetic waters, one simulating wastewater from the textile industry and the other one simulating wastewater from the cassava starch industry, were prepared and treated by homogeneous Fenton process and heterogeneous photocatalysis, respectively. Untreated and treated synthetic waters and their dilutions were placed into compartments of the non-forced exposure system, in which zebrafish (Danio rerio), the indicator organism, could select the environment of its preference. Basic physical–chemical and chemical parameters of untreated and treated synthetic waters were measured. The preference and avoidance responses allowed verification of whether or not the quality of the water was improved due to the treatment. The results of these assays can be a complement to conventional parameters of water quality.
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6
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Razmara P, Sharpe J, Pyle GG. Rainbow trout (Oncorhynchus mykiss) chemosensory detection of and reactions to copper nanoparticles and copper ions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:113925. [PMID: 32369894 DOI: 10.1016/j.envpol.2020.113925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/20/2019] [Accepted: 01/05/2020] [Indexed: 06/11/2023]
Abstract
Copper is known to interfere with fish olfaction. Although the chemosensory detection and olfactory toxicity of copper ions (Cu2+) has been heavily studied in fish, the olfactory-driven detection of copper nanoparticles (CuNPs)-a rapidly emerging contaminant to aquatic systems-remains largely unknown. This study aimed to investigate the olfactory response of rainbow trout to equitoxic concentrations of CuNPs or Cu2+ using electro-olfactography (EOG, a neurophysiological technique) and olfactory-mediated behavioural assay. In the first experiment, the concentration of contaminants known to impair olfaction by 20% over 24 h (EOG-based 24-h IC20s of 220 and 3.5 μg/L for CuNPs and Cu2+, respectively) were tested as olfactory stimuli using both neurophysiological and behavioural assays. In the second experiment, to determine whether the presence of CuNPs or Cu2+ can affect the ability of fish to perceive a social cue (taurocholic acid (TCA)), fish were acutely exposed to one form of Cu-contaminants (approximately 15 min). Following exposure, olfactory sensitivity was measured by EOG and olfactory-mediated behaviour within a choice maze was recorded in the presence of TCA. Results of neurophysiological and behavioural experiments demonstrate that rainbow trout can detect and avoid the IC20 of CuNPs. The IC20 of Cu2+ was below the olfactory detection threshold of rainbow trout, as such, fish did not avoid Cu2+. The high sensitivity of behavioural endpoints revealed a lack of aversion response to TCA in CuNP-exposed fish, despite this change not being present utilizing EOG. The reduced response to TCA during the brief exposure to CuNPs may be a result of either olfactory fatigue or blockage of olfactory sensory neurons (OSNs) by CuNPs. The observed behavioural interference caused by CuNP exposure may indicate that CuNPs have the ability to interfere with other behaviours potentially affecting fitness and survival. Our findings also revealed the differential response of OSNs to CuNPs and Cu2+.
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Affiliation(s)
- Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada.
| | - Justin Sharpe
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
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7
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Evans MS, McMaster M, Muir DCG, Parrott J, Tetreault GR, Keating J. Forage fish and polycyclic aromatic compounds in the Fort McMurray oil sands area: Body burden comparisons with environmental distributions and consumption guidelines. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113135. [PMID: 31550651 DOI: 10.1016/j.envpol.2019.113135] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/09/2019] [Accepted: 08/28/2019] [Indexed: 05/05/2023]
Abstract
The Fort McMurray region in northeastern Alberta (Canada) is rich in natural sources of polycyclic aromatic compounds (PACs) from exposed bitumen beds; anthropogenic sources are being released with increased oil sands industry expansion. Here we report on investigations of PACs (47 compounds) in three species of forage fish collected during the 2012-2013 Joint Oil Sands Monitoring Program (JOSMP) fish health investigations and compare results with PAC data for sediment and water collected under JOSMP and earlier programs. PAC concentrations in sediments varied three orders in magnitude and were highest at downstream tributary mouths, which flowed through the exposed McMurray Formation, and along reaches of the Athabasca River where the formation was exposed. PAC concentrations in water were less variable but with higher concentrations near exposed bitumen beds. Forage fish exhibited the weakest spatial gradients in ΣPACs concentration, which averaged 102 ± 32 ng/g in trout-perch from the Athabasca River, 125 ± 22 ng/g in lake chub from the Ells River, and 278 ± 267 ng/g in slimy sculpin from the Steepbank, Firebag, and Dunkirk Rivers. Low-molecular weight compounds, particularly naphthalenes and fluorenes, dominated fish PACs. Phenanthrenes occurred in greater percent composition in fish caught in areas where PAC concentrations in sediments were higher due to the proximity of bitumen sources than in other areas. Dibenzothiophene, a major component of bitumen PAC, was a minor component of fish ΣPACs. Forage fish PAC concentrations were below fish consumption guidelines established by the European Commission (2011) and for the reopening of the commercial fisheries closed by the Deepwater Horizon oil spill. PAC concentrations in forage fish were similar to concentrations observed in many other studies (fish market surveys, estuaries, and marine waters) and lower than in fish sampled from highly impacted areas (near refineries, harbors, and other industrialized areas).
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Affiliation(s)
- M S Evans
- Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada.
| | - M McMaster
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - D C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - J Parrott
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - G R Tetreault
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - J Keating
- Watershed Hydrology and Ecology Research Division, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
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8
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Lari E, Steinkey D, Razmara P, Mohaddes E, Pyle GG. Oil sands process-affected water impairs the olfactory system of rainbow trout (Oncorhynchus mykiss). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 170:62-67. [PMID: 30529621 DOI: 10.1016/j.ecoenv.2018.11.105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
Oil sands process-affected water (OSPW), a byproduct of the extraction of bitumen in the surface mining of oil sands, is currently stored in massive on-site tailings ponds. Determining the potential effects of OSPW on aquatic ecosystems is of main concern to oil sands companies and legislators concerned about the reclamation of mining sites. In the present study, the interaction of OSPW with the chemosensory system of rainbow trout was studied. Using an electro-olfactography (EOG) technique, a 24 h inhibition curve was established and concentrations that inhibit the olfactory system by 20% and 80% (IC20 and IC80) were estimated at 3% and 22% OSPW, respectively. To study the interaction of exposure time and concentration along with the mechanism of the toxic effects, rainbow trout were exposed to 3% and 22% OSPW for 2, 24, and 96 h. An EOG investigation of olfactory sensitivity demonstrated a positive interaction between exposure time and concentration of OSPW concentration, because an increase in either or both elevated the inhibitory effect. To investigate whether or not structural damage of the olfactory epithelium could account for the observed inhibitory effects of OSPW on fish olfaction, the ultrastructure of the olfactory epithelium of exposed fish was investigated using scanning electron microscopy (SEM) and light microscopy (LM). The SEM micrographs showed no changes in the structure of the olfactory epithelium. The light micrographs revealed an increase in the number of mucous cells in 22% OSPW. The results of the present study demonstrated that exposure to OSPW impairs the olfactory system of rainbow trout and its effects increase gradually with increasing exposure time. The present study demonstrated that structural epithelial damage did not contribute to the inhibitory effects of OSPW on the olfactory system.
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Affiliation(s)
- Ebrahim Lari
- Department of Biological Sciences, University of Lethbridge, Lethbridge AB T1K 3M4, Canada.
| | - Dylan Steinkey
- Department of Biological Sciences, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
| | - Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
| | - Effat Mohaddes
- Department of Biological Sciences, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
| | - Greg G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge AB T1K 3M4, Canada
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9
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Lari E, Razmara P, Bogart SJ, Azizishirazi A, Pyle GG. An epithelium is not just an epithelium: Effects of Na, Cl, and pH on olfaction and/or copper-induced olfactory deficits. CHEMOSPHERE 2019; 216:117-123. [PMID: 30366265 DOI: 10.1016/j.chemosphere.2018.10.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 06/08/2023]
Abstract
While the toxic effects of several substances on fish olfaction are well known, studies on how water chemistry affects contaminant-induced olfactory toxicity are rare. In the present study, the effect of water pH or Na concentration on fish olfactory response and Cu-induced olfactory toxicity was investigated. Also, the effects of two sodium salts, NaCl and NaNO3, on olfaction were studied. Juvenile rainbow trout were exposed to 6 and 32 μg/L Cu, each under five different conditions (pH 9, pH 6.5, 20 or 40 mg/L sodium added, or culture water), for 10 days before characterizing fish olfactory response using electro-olfactography (EOG). The results demonstrated that reducing the pH to 6.5 or adding 20 or 40 mg/L Na impairs the fish response to a standard olfactory cue. None of the water treatments were protective against, or synergic with, the toxic effect of Cu on the olfactory system. Of the two Na salts, NaCl caused significantly higher impairment than NaNO3. The results of the present study demonstrate that water quality modifies contaminant-induced olfactory toxicity, but differently than what is known for other tissues (i.e. gill).
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Affiliation(s)
- Ebrahim Lari
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
| | - Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Sarah J Bogart
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Ali Azizishirazi
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; British Columbia Ministry of Environment and Climate Change Strategy, 525 Superior Street, Victoria, BC V8V 1T7, Canada
| | - Greg G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
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10
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Lazzari M, Bettini S, Milani L, Maurizii MG, Franceschini V. Differential nickel-induced responses of olfactory sensory neuron populations in zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 206:14-23. [PMID: 30415017 DOI: 10.1016/j.aquatox.2018.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/15/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
The olfactory epithelium of fish includes three main types of olfactory sensory neurons (OSNs). Whereas ciliated (cOSNs) and microvillous olfactory sensory neurons (mOSNs) are common to all vertebrates, a third, smaller group, the crypt cells, is exclusive for fish. Dissolved pollutants reach OSNs, thus resulting in impairment of the olfactory function with possible neurobehavioral damages, and nickel represents a diffuse olfactory toxicant. We studied the effects of three sublethal Ni2+ concentrations on the different OSN populations of zebrafish that is a widely used biological model. We applied image analysis with cell count and quantification of histochemically-detected markers of the different types of OSNs. The present study shows clear evidence of a differential responses of OSN populations to treatments. Densitometric values for Gα olf, a marker of cOSNs, decreased compared to control and showed a concentration-dependent effect in the ventral half of the olfactory rosette. The densitometric analysis of TRPC2, a marker of mOSNs, revealed a statistically significant reduction compared to control, smaller than the decrease for Gα olf and without concentration-dependent effects. After exposure, olfactory epithelium stained with anti-calretinin, a marker of c- and mOSNs, revealed a decrease in thickness while the sensory area appeared unchanged. The thickness reduction together with increased densitometric values for HuC/D, a marker of mature and immature neurons, suggests that the decrements in Gα olf and TRPC2 immunostaining may depend on cell death. However, reductions in the number of apical processes and of antigen expression could be a further explanation. We hypothesize that cOSNs are more sensitive than mOSNs to Ni2+ exposure. Difference between subpopulations of OSNs or differences in water flux throughout the olfactory cavity could account for the greater susceptibility of the OSNs located in the ventral half of the olfactory rosette. Cell count of anti-TrkA immunopositive cells reveals that Ni2+ exposure does not affect crypt cells. The results of this immunohistochemical study are not in line with those obtained by electro-olfactogram.
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Affiliation(s)
- Maurizio Lazzari
- Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126 Bologna, Italy.
| | - Simone Bettini
- Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126 Bologna, Italy
| | - Liliana Milani
- Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126 Bologna, Italy
| | - Maria Gabriella Maurizii
- Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126 Bologna, Italy
| | - Valeria Franceschini
- Department of Biological, Geological and Environmental Sciences, University of Bologna, 40126 Bologna, Italy
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11
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Araújo CVM, Roque D, Blasco J, Ribeiro R, Moreira-Santos M, Toribio A, Aguirre E, Barro S. Stress-driven emigration in complex field scenarios of habitat disturbance: The heterogeneous multi-habitat assay system (HeMHAS). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:31-36. [PMID: 29980082 DOI: 10.1016/j.scitotenv.2018.06.336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
Lines of evidence used in ecological risk assessment (ERA) are essentially three: chemistry, biology and ecotoxicology. Until now, the fundamental assumption made when measuring ecological risks is that organisms are forcedly exposed to stressors. However, when organisms can avoid disturbed habitats by escaping to less stressful areas, the assumption that exposure is mandatory to pose risk may not match field disturbance scenarios. A non-forced exposure approach using a linear free-choice multi-compartmented system has been proposed previously as a complementary tool to assess the effects on organisms' spatial avoidance/preference responses. Yet, the linearity of the latter system limits avoidance measurements to one spatial dimension. A novel, heterogeneous multi-habitat assay system (HeMHAS) consisting of 18 connected circular compartments (3 compartments on a vertical axis in each one of 6 zones on a longitudinal axis; a 2D system) is put forward here to be used in heterogeneous-habitat selection studies, as it makes it possible to assess the ability of organisms to detect contamination and other stressors and select more favorable habitats. In the present study, the avoidance to copper by zebrafish (Danio rerio) was tested after exposing organisms to a copper gradient in the HeMHAS and compared with that in the linear system. Avoidance occurred for all copper concentrations: 43% in the lowest (21 μg·L-1) to 72% in the highest (221 μg·L-1). Results obtained within the HeMHAS (AC50: 60 μg·L-1) were statistically (p = 0.72) similar to avoidance of copper by D. rerio in the linear non-forced system (AC50: 89 μg·L-1). In summary, the simulation of a copper gradient in the HeMHAS (2D system) allowed to assess the potential repellency of copper to zebrafish and to corroborate the ability of organisms to detect and avoid potentially toxic concentrations.
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Affiliation(s)
- Cristiano V M Araújo
- Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), 11510 Puerto Real, Cádiz, Spain; Center for Functional Ecology (CEF), University of Coimbra, Portugal.
| | - David Roque
- Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), 11510 Puerto Real, Cádiz, Spain
| | - Julián Blasco
- Department of Ecology and Coastal Management, Institute of Marine Sciences of Andalusia (CSIC), 11510 Puerto Real, Cádiz, Spain
| | - Rui Ribeiro
- Center for Functional Ecology (CEF), University of Coimbra, Portugal
| | | | - Asier Toribio
- Aquatic BioTechnology, El Puerto de Santa María, Spain
| | | | - Sergio Barro
- Aquatic BioTechnology, El Puerto de Santa María, Spain
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