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Hashim AR, Bashir DW, Rashad E, Galal MK, Rashad MM, Khalil HMA, Deraz NM, S M EG. Neuroprotective Assessment of Betaine against Copper Oxide Nanoparticle-Induced Neurotoxicity in the Brains of Albino Rats: A Histopathological, Neurochemical, and Molecular Investigation. ACS Chem Neurosci 2024; 15:1684-1701. [PMID: 38564598 DOI: 10.1021/acschemneuro.3c00810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024] Open
Abstract
Copper oxide nanoparticles (CuO-NPs) are commonly used metal oxides. Betaine possesses antioxidant and neuroprotective activities. The current study aimed to investigate the neurotoxic effect of CuO-NPs on rats and the capability of betaine to mitigate neurotoxicity. Forty rats; 4 groups: group I a control, group II intraperitoneally CuO-NPs (0.5 mg/kg/day), group III orally betaine (250 mg/kg/day) and CuO-NPs, group IV orally betaine for 28 days. Rats were subjected to neurobehavioral assessments. Brain samples were processed for biochemical, molecular, histopathological, and immunohistochemical analyses. Behavioral performance of betaine demonstrated increasing locomotion and cognitive abilities. Group II exhibited significantly elevated malondialdehyde (MDA), overexpression of interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α). Significant decrease in glutathione (GSH), and downregulation of acetylcholine esterase (AChE), nuclear factor erythroid 2-like protein 2 (Nrf-2), and superoxide dismutase (SOD). Histopathological alterations; neuronal degeneration, pericellular spaces, and neuropillar vacuolation. Immunohistochemically, an intense immunoreactivity is observed against IL-1β and glial fibrillary acidic protein (GFAP). Betaine partially neuroprotected against CuO-NPs associated alterations. A significant decrease at MDA, downregulation of IL-1β, and TNF-α, a significant increase at GSH, and upregulation of AChE, Nrf-2, and SOD. Histopathological alterations partially ameliorated. Immunohistochemical intensity of IL-1β and GFAP reduced. It is concluded that betaine neuroprotected against most of CuO-NP neurotoxic effects through antioxidant and cell redox system stimulating efficacy.
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Affiliation(s)
- Asmaa R Hashim
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Dina W Bashir
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Eman Rashad
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Mona K Galal
- Biochemistry and Chemistry of Nutrition Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Maha M Rashad
- Biochemistry and Chemistry of Nutrition Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Heba M A Khalil
- Veterinary Hygiene and Management Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Nasrallah M Deraz
- Physical Chemistry Department, National Research Centre, Dokki, Giza, Egypt
| | - El-Gharbawy S M
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
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Shalaby OE, Ahmed YH, Mekkawy AM, Mahmoud MY, Khalil HMA, Elbargeesy GA. Assessment of the neuroprotective effect of selenium-loaded chitosan nanoparticles against silver nanoparticles-induced toxicity in rats. Neurotoxicology 2023; 95:232-243. [PMID: 36822375 DOI: 10.1016/j.neuro.2023.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023]
Abstract
BACKGROUND With the recent growth in the applications of silver nanoparticles (Ag-NPs), worries about their harmful effects are increasing. Selenium plays a vital role in the antioxidant defense system as well as free radical scavenging activity. OBJECTIVES This study aims to inspect the neuroprotective effect of selenium-loaded chitosan nanoparticles (CS-SeNPs) against the adverse impact of Ag-NPs on brain tissue in adult rats. DESIGN Rats were divided into four groups: group I (control) was administered distilled water (0.5 mL/kg), group II was administered Ag-NPs (100 mg/kg), group III was administered Ag-NPs (100 mg/kg) and CS- SeNPs (0.5 mg/kg) and group IV received only CS- SeNPs (0.5 mg/kg) daily by oral gavage. After 60 days, rats were subjected to behavioral assessment and then euthanized. Brain tissues were obtained for estimation of total antioxidant capacity (TAC), malondialdehyde (MDA), 8-hydroxy-2-deoxy Guanosine (8-OHdG), and Nuclear Factor Erythroid 2 Like Protein 2 (Nrf2). Also, histological examination of the brain and immunohistochemical detection of glial fibrillary acidic protein (GFAP) were investigated RESULTS: exposure to Ag-NPs induced marked neurotoxicity in the brain tissue of rats that was manifested by decreased levels of TAC and Nrf2 with increased levels of MDA and 8-OHdG. Also, various pathological lesions with an increase in the number of GFAP immunoreactive cells were detected. While brain tissue of rats received Ag-NPs plus CS-SeNPs group (III) revealed significantly fewer pathological changes. CONCLUSION Co-administration of CS-SeNPs significantly ameliorates most of the Ag-NPs-induced brain damage.
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Affiliation(s)
- Omnia E Shalaby
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - Yasmine H Ahmed
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - Aya M Mekkawy
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - Mohamed Y Mahmoud
- Department of Toxicology and Forensic Medicine, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - Heba M A Khalil
- Department of Veterinary Hygiene and Management, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - G A Elbargeesy
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Cairo University, Egypt.
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Bashir DW, Rashad MM, Ahmed YH, Drweesh EA, Elzahany EAM, Abou-El-Sherbini KS, El-Leithy EMM. The ameliorative effect of nanoselenium on histopathological and biochemical alterations induced by melamine toxicity on the brain of adult male albino rats. Neurotoxicology 2021; 86:37-51. [PMID: 34216684 DOI: 10.1016/j.neuro.2021.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/16/2021] [Accepted: 06/25/2021] [Indexed: 01/01/2023]
Abstract
Melamine is a chemical substance used as a food adulterant because of its high nitrogen content; it is known to induce neurotoxicity, thereby adversely affecting the central nervous system. The biocompatibility, bioavailability, lower toxicity, and the large surface area of nanosized selenium relative to its other forms indicate that selenium nanoparticles (SeNPs) have a potential ameliorative effect against melamine-induced neurotoxicity. In this study, we tested this hypothesis using 40 adult male albino rats that were randomly assigned into four groups (n = 10 per group): group I rats served as the untreated negative controls and were fed with standard diet and distilled water; group II rats were orally treated with melamine (300 mg/kg body weight/d); group III rats orally received melamine (300 mg/kg body weight/d) and SeNPs (2 mg/kg body weight/d); and group IV rats received SeNPs only (2 mg/kg body weight/d) for 28 days. Blood and brain samples were collected from all rats and processed for biochemical, histopathological, and immunohistochemical investigations. SeNPs were encapsulated in starch as a natural stabilizer and a size-controlling agent (SeNP@starch). The prepared SeNPs were characterized using different techniques. Inductively coupled plasma-optical emission spectrometry (ICP-OES) indicated that the percentage of selenium loaded in starch was 1.888 %. Powder x-ray diffractometer (XRD) was used to investigate the crystalline structure of the Se-NP@starch, to be tubular and composed of amorphous starch as well as metallic selenium. Thermogravimetric analysis confirmed the thermal stability of the product and determined the interactions among the different components. Transmission electron microscope demonstrated the spherical shape of SeNPs and their dispersion into starch surface as well as evaluating their size in nanoscale (range 20-140 nm). Our results revealed that the melamine- exposed rats had significantly elevated in malondialdehyde levels, significantly reduced in total antioxidant capacity, down-regulated expression of the antioxidant related genes Nrf2 (nuclear factor erythroid 2-related factor 2) and GPx (glutathione peroxidase), as well as up-regulated expression of the apoptosis-related gene Bax (B-cell lymphoma 2-associated X protein), with down regulation of Bcl-2 (B-cell lymphoma 2). Histopathological examination exhibited several alterations in the cerebrum, cerebellum, and hippocampus of the treated rats compared with the controls. Neuronal degeneration, vacuolation of the neuropils, and pericellular and perivascular spaces were observed. In addition, the pyramidal and granular cell layers of the hippocampus and cerebellum, respectively, were found to have significantly reduced thickness. Furthermore, a significant decrease in the percentage area of the glial fibrillary acidic protein and a significant increase in the percentage area of caspase-3 were noted. On the other hand, co-treatment with SeNPs partially ameliorated these alterations. A significant reduction in malondialdehyde levels; a non- significant elevation in total antioxidant capacity; up-regulation, upregulation of Nrf2, GPx, and Bcl-2 and downregulation of Bax were recorded. Neuronal degeneration, vacuolation of neuropils, and pericellular spaces were reduced. The pyramidal and granular cell layers restored their normal thickness. The percentage area of the glial fibrillary acidic protein significantly increased, whereas that of caspase-3 significantly decreased. In conclusion, SeNPs have an ameliorative effect against melamine-induced neurotoxicity in albino rats.
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Affiliation(s)
- Dina W Bashir
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Maha M Rashad
- Biochemistry and Chemistry of Nutrition Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Yasmine H Ahmed
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
| | - Elsayed A Drweesh
- Department of Inorganic Chemistry, National Research Centre, Giza, Egypt
| | - Eman A M Elzahany
- Department of Inorganic Chemistry, National Research Centre, Giza, Egypt
| | | | - Ebtihal M M El-Leithy
- Cytology and Histology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
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Petroff R, Hendrix A, Shum S, Grant KS, Lefebvre KA, Burbacher TM. Public health risks associated with chronic, low-level domoic acid exposure: A review of the evidence. Pharmacol Ther 2021; 227:107865. [PMID: 33930455 DOI: 10.1016/j.pharmthera.2021.107865] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/13/2022]
Abstract
Domoic acid (DA), the causative agent for the human syndrome Amnesic Shellfish Poisoning (ASP), is a potent, naturally occurring neurotoxin produced by common marine algae. DA accumulates in seafood, and humans and wildlife alike can subsequently be exposed when consuming DA-contaminated shellfish or finfish. While strong regulatory limits protect people from the acute effects associated with ASP, DA is an increasingly significant public health concern, particularly for coastal dwelling populations, and there is a growing body of evidence suggesting that there are significant health consequences following repeated exposures to levels of the toxin below current safety guidelines. However, gaps in scientific knowledge make it difficult to precisely determine the risks of contemporary low-level exposure scenarios. The present review characterizes the toxicokinetics and neurotoxicology of DA, discussing results from clinical and preclinical studies after both adult and developmental DA exposure. The review also highlights crucial areas for future DA research and makes the case that DA safety limits need to be reassessed to best protect public health from deleterious effects of this widespread marine toxin.
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Affiliation(s)
- Rebekah Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Alicia Hendrix
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kimberly S Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, University of Washington, Seattle, WA, USA
| | - Kathi A Lefebvre
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Blvd. East, Seattle, WA, USA
| | - Thomas M Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, University of Washington, Seattle, WA, USA; Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle,WA, USA.
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Rodríguez-López S, Escobedo Martínez MF, Junquera L, García-Pola M. Two-Dimensional Analysis of Digital Images through Vector Graphic Editors in Dentistry: New Calibration and Analysis Protocol Based on a Scoping Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18094497. [PMID: 33922692 PMCID: PMC8122989 DOI: 10.3390/ijerph18094497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/18/2021] [Accepted: 04/21/2021] [Indexed: 11/16/2022]
Abstract
This review was carried out to analyse the functions of three Vector Graphic Editor applications (VGEs) applicable to clinical or research practice, and through this we propose a two-dimensional image analysis protocol in a VGE. We adapted the review method from the PRISMA-ScR protocol. Pubmed, Embase, Web of Science, and Scopus were searched until June 2020 with the following keywords: Vector Graphics Editor, Vector Graphics Editor Dentistry, Adobe Illustrator, Adobe Illustrator Dentistry, Coreldraw, Coreldraw Dentistry, Inkscape, Inkscape Dentistry. The publications found described the functions of the following VGEs: Adobe Illustrator, CorelDRAW, and Inkscape. The possibility of replicating the procedures to perform the VGE functions was analysed using each study’s data. The search yielded 1032 publications. After the selection, 21 articles met the eligibility criteria. They described eight VGE functions: line tracing, landmarks tracing, linear measurement recording, angular measurement recording, image calibration, image overlay, file transfer, and vector graphics development. The features offered by the VGEs bring great precision and objectivity to two-dimensional image analysis. The image analysis and editing procedures are currently not protocolised. Thus, a protocol for image calibration and measurement recording is proposed in order to guarantee the protocol’s replication.
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Affiliation(s)
- Samuel Rodríguez-López
- Department of Operative Dentistry, School of Dentistry, University of Oviedo, C/. Catedrático Serrano s/n., 33006 Oviedo, Spain;
- Correspondence: ; Tel.: +34-600-74-27-58
| | - Matías Ferrán Escobedo Martínez
- Department of Operative Dentistry, School of Dentistry, University of Oviedo, C/. Catedrático Serrano s/n., 33006 Oviedo, Spain;
| | - Luis Junquera
- Department of Oral and Maxillofacial Surgery and Oral Medicine, School of Dentistry, University of Oviedo, C/. Catedrático Serrano s/n., 33006 Oviedo, Spain; (L.J.); (M.G.-P.)
| | - María García-Pola
- Department of Oral and Maxillofacial Surgery and Oral Medicine, School of Dentistry, University of Oviedo, C/. Catedrático Serrano s/n., 33006 Oviedo, Spain; (L.J.); (M.G.-P.)
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Demars F, Clark K, Wyeth MS, Abrams E, Buckmaster PS. A single subconvulsant dose of domoic acid at mid-gestation does not cause temporal lobe epilepsy in mice. Neurotoxicology 2018; 66:128-137. [PMID: 29625197 PMCID: PMC5940543 DOI: 10.1016/j.neuro.2018.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 11/19/2022]
Abstract
Harmful blooms of domoic acid (DA)-producing algae are a problem in oceans worldwide. DA is a potent glutamate receptor agonist that can cause status epilepticus and in survivors, temporal lobe epilepsy. In mice, one-time low-dose in utero exposure to DA was reported to cause hippocampal damage and epileptiform activity, leading to the hypothesis that unrecognized exposure to DA from contaminated seafood in pregnant women can damage the fetal hippocampus and initiate temporal lobe epileptogenesis. However, development of epilepsy (i.e., spontaneous recurrent seizures) has not been tested. In the present study, long-term seizure monitoring and histology was used to test for temporal lobe epilepsy following prenatal exposure to DA. In Experiment One, the previous study's in utero DA treatment protocol was replicated, including use of the CD-1 mouse strain. Afterward, mice were video-monitored for convulsive seizures from 2 to 6 months old. None of the CD-1 mice treated in utero with vehicle or DA was observed to experience spontaneous convulsive seizures. After seizure monitoring, mice were evaluated for pathological evidence of temporal lobe epilepsy. None of the mice treated in utero with DA displayed the hilar neuron loss that occurs in patients with temporal lobe epilepsy and in the mouse pilocarpine model of temporal lobe epilepsy. In Experiment Two, a higher dose of DA was administered to pregnant FVB mice. FVB mice were tested as a potentially more sensitive strain, because they have a lower seizure threshold, and some females spontaneously develop epilepsy. Female offspring were monitored with continuous video and telemetric bilateral hippocampal local field potential recording at 1-11 months old. A similar proportion of vehicle- and DA-treated female FVB mice spontaneously developed epilepsy, beginning in the fourth month of life. Average seizure frequency and duration were similar in both groups. Seizure frequency was lower than that of positive-control pilocarpine-treated mice, but seizure duration was similar. None of the mice treated in utero with vehicle or DA displayed hilar neuron loss or intense mossy fiber sprouting, a form of aberrant synaptic reorganization that develops in patients with temporal lobe epilepsy and in pilocarpine-treated mice. FVB mice that developed epilepsy (vehicle- and DA-treated) displayed mild mossy fiber sprouting. Results of this study suggest that a single subconvulsive dose of DA at mid-gestation does not cause temporal lobe epilepsy in mice.
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Affiliation(s)
- Fanny Demars
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; VetAgro Sup, School of Veterinary Medicine, Lyon, France; Paris Descartes University, Paris, France
| | - Kristen Clark
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, United States
| | - Megan S Wyeth
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Emily Abrams
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Paul S Buckmaster
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States.
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Cook PF, Reichmuth C, Rouse A, Dennison S, Van Bonn B, Gulland F. Natural exposure to domoic acid causes behavioral perseveration in Wild Sea lions: Neural underpinnings and diagnostic application. Neurotoxicol Teratol 2016; 57:95-105. [DOI: 10.1016/j.ntt.2016.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 01/27/2023]
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Mills BD, Pearce HL, Khan O, Jarrett BR, Fair DA, Lahvis GP. Prenatal domoic acid exposure disrupts mouse pro-social behavior and functional connectivity MRI. Behav Brain Res 2016; 308:14-23. [PMID: 27050322 PMCID: PMC4918767 DOI: 10.1016/j.bbr.2016.03.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/18/2016] [Accepted: 03/22/2016] [Indexed: 12/29/2022]
Abstract
Domoic acid (DA) is a toxin produced by marine algae and known primarily for its role in isolated outbreaks of Amnestic Shellfish Poisoning and for the damage it inflicts on marine mammals, particularly California sea lions. Lethal effects of DA are often preceded by seizures and coma. Exposure to DA during development can result in subtle and highly persistent effects on brain development and include behavioral changes that resemble diagnostic features of schizophrenia and anomalies in social behavior we believe are relevant to autism spectrum disorder (ASD). To more fully examine this hypothesis, we chose to examine adolescent mice exposed in utero to DA for endpoints relevant to ASD, specifically changes in social behavior and network structure, the latter measured by resting state functional connectivity (rs-fcMRI). We found that male offspring exposed in utero to DA expressed reproducible declines in social interaction and atypical patterns of functional connectivity in the anterior cingulate, a region of the default mode network that is critical for social functioning. We also found disruptions in global topology in regions involved in the processing of reward, social, and sensory experiences. Finally, we found that DA exposed males expressed a pattern of local over-connectivity. These anomalies in brain connectivity bear resemblance to connectivity patterns in ASD and help validate DA-exposed mice as a model of this mental disability.
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Affiliation(s)
- Brian D Mills
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - Hadley L Pearce
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - Omar Khan
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - Ben R Jarrett
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - Damien A Fair
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States; Department of Psychiatry, Oregon Health & Science University, Portland, OR 97239, United States; Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR 97239, United States
| | - Garet P Lahvis
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States.
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Vieira AC, Cifuentes JM, Bermúdez R, Ferreiro SF, Castro AR, Botana LM. Heart Alterations after Domoic Acid Administration in Rats. Toxins (Basel) 2016; 8:E68. [PMID: 26978401 PMCID: PMC4810213 DOI: 10.3390/toxins8030068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/21/2016] [Accepted: 02/22/2016] [Indexed: 11/24/2022] Open
Abstract
Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. In the present study we have addressed the long-term toxicological effects (30 days) of DA intraperitoneal administration in rats. Different histological techniques were employed in order to study DA toxicity in heart, an organ which has not been thoroughly studied after DA intoxication to date. The presence of DA was detected by immunohistochemical assays, and cellular alterations were observed both by optical and transmission electron microscopy. Although histological staining methods did not provide any observable tissue damage, transmission electron microscopy showed several injuries: a moderate lysis of myofibrils and loss of mitochondrial conformation. This is the first time the association between heart damage and the presence of the toxin has been observed.
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Affiliation(s)
- Andres C Vieira
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo 27002, Spain.
| | - José Manuel Cifuentes
- Departamento de Anatomía, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo 27002, Spain.
| | - Roberto Bermúdez
- Departamento de Anatomía, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo 27002, Spain.
| | - Sara F Ferreiro
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo 27002, Spain.
| | - Albina Román Castro
- Rede de Infraestruturas de Apoio á Investigación e ao Desenvolvemento Tecnolóxico (RIADT) Lugo, Universidad de Santiago de Compostela, Lugo 27002, Spain.
| | - Luis M Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo 27002, Spain.
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Zuloaga DG, Lahvis GP, Mills B, Pearce HL, Turner J, Raber J. Fetal domoic acid exposure affects lateral amygdala neurons, diminishes social investigation and alters sensory-motor gating. Neurotoxicology 2016; 53:132-140. [PMID: 26797589 PMCID: PMC5929993 DOI: 10.1016/j.neuro.2016.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/14/2016] [Accepted: 01/15/2016] [Indexed: 01/01/2023]
Abstract
Domoic acid (DA) is an algal neurotoxin that accumulates in marine fish and shellfish. DA can move across the placenta and concentrate in amniotic fluid, which can be swallowed during late gestation. DA also transfers to infants via milk. Preclinical studies to determine effects of developmental DA expose have primarily involved DA exposure during the postnatal period and little is known about late CNS effects following prenatal DA. In the present study, we tested the hypothesis that prenatal exposure of FVB mice to low levels of DA would result in diminished social interaction and sensory motor gating associated with alterations in parvalbumin immunoreactivity in relevant brain regions undergoing development during and following DA exposure. In addition to parvalbumin, we stained with NeuN for a neuronal specific nuclear protein to determine if neuronal loss followed prenatal DA exposure. A single moderate dose of DA administered during gestation produces diminishes social investigation and alters sensorimotor gating, behavioral effects more pronounced in males than females. These behavioral changes were associated with discrete alterations in the parvalbumin-positive subtype of GABAergic neurons in the dentate gyrus and lateral amygdala.
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Affiliation(s)
- D G Zuloaga
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - G P Lahvis
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States.
| | - B Mills
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - H L Pearce
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - J Turner
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States
| | - J Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States; Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, United States.
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Buckmaster PS, Wen X, Toyoda I, Gulland FMD, Van Bonn W. Hippocampal neuropathology of domoic acid-induced epilepsy in California sea lions (Zalophus californianus). J Comp Neurol 2014; 522:1691-706. [PMID: 24638960 DOI: 10.1002/cne.23509] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/21/2013] [Accepted: 11/21/2013] [Indexed: 12/24/2022]
Abstract
California sea lions (Zalophus californianus) are abundant human-sized carnivores with large gyrencephalic brains. They develop epilepsy after experiencing status epilepticus when naturally exposed to domoic acid. We tested whether sea lions previously exposed to DA (chronic DA sea lions) display hippocampal neuropathology similar to that of human patients with temporal lobe epilepsy. Hippocampi were obtained from control and chronic DA sea lions. Stereology was used to estimate numbers of Nissl-stained neurons per hippocampus in the granule cell layer, hilus, and pyramidal cell layer of CA3, CA2, and CA1 subfields. Adjacent sections were processed for somatostatin immunoreactivity or Timm-stained, and the extent of mossy fiber sprouting was measured stereologically. Chronic DA sea lions displayed hippocampal neuron loss in patterns and extents similar but not identical to those reported previously for human patients with temporal lobe epilepsy. Similar to human patients, hippocampal sclerosis in sea lions was unilateral in 79% of cases, mossy fiber sprouting was a common neuropathological abnormality, and somatostatin-immunoreactive axons were exuberant in the dentate gyrus despite loss of immunopositive hilar neurons. Thus, hippocampal neuropathology of chronic DA sea lions is similar to that of human patients with temporal lobe epilepsy.
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Affiliation(s)
- Paul S Buckmaster
- Department of Comparative Medicine, Stanford University, Stanford, California, 94305; Department of Neurology & Neurological Sciences, Stanford University, Stanford, California, 94305
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Domoic acid epileptic disease. Mar Drugs 2014; 12:1185-207. [PMID: 24663110 PMCID: PMC3967204 DOI: 10.3390/md12031185] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/08/2014] [Accepted: 02/08/2014] [Indexed: 12/23/2022] Open
Abstract
Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.
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Rao DB, Little PB, Sills R. Subsite awareness in neuropathology evaluation of National Toxicology Program (NTP) studies: a review of select neuroanatomical structures with their functional significance in rodents. Toxicol Pathol 2013; 42:487-509. [PMID: 24135464 PMCID: PMC3965620 DOI: 10.1177/0192623313501893] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This review article is designed to serve as an introductory guide in neuroanatomy for toxicologic pathologists evaluating general toxicity studies. The article provides an overview of approximately 50 neuroanatomical subsites and their functional significance across 7 transverse sections of the brain. Also reviewed are 3 sections of the spinal cord, cranial and peripheral nerves (trigeminal and sciatic, respectively), and intestinal autonomic ganglia. The review is limited to the evaluation of hematoxylin and eosin-stained tissue sections, as light microscopic evaluation of these sections is an integral part of the first-tier toxicity screening of environmental chemicals, drugs, and other agents. Prominent neuroanatomical sites associated with major neurological disorders are noted. This guide, when used in conjunction with detailed neuroanatomic atlases, may aid in an understanding of the significance of functional neuroanatomy, thereby improving the characterization of neurotoxicity in general toxicity and safety evaluation studies.
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Affiliation(s)
- Deepa B. Rao
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina
| | - Peter B. Little
- Consultant, Experimental Pathology Laboratories, Inc., Research Triangle Park, North Carolina
| | - Robert Sills
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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Chang IY, Kim JH, Cho KW, Yoon SP. Acute responses of DNA repair proteins and StarD6 in rat hippocampus after domoic acid-induced excitotoxicity. Acta Histochem 2013; 115:234-9. [PMID: 22883302 DOI: 10.1016/j.acthis.2012.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/04/2012] [Accepted: 07/05/2012] [Indexed: 10/28/2022]
Abstract
StarD6, which might be considered to be neuroprotective, and DNA repair proteins can play a role against oxidative damages by excitotoxin in the nervous system. In order to investigate the relationship between StarD6 and DNA repair proteins, excitotoxicity was induced by domoic acid in male Sprague-Dawley rats. Western blot analysis revealed transitorily elevated levels in StarD6, apurinic/apyrimidinic endonuclease (APE) and 8-oxoguanine DNA-glycosylase (Ogg1) in accord with the DNA damage marker phosphorylated H2AX. Immunohistochemistry revealed that increased intensity was transiently seen not only in the Stratum (Str.) radiatum and Str. lacunosum-moleculare with StarD6 and APE, but also in the Str. pyramidale with Ogg1. Intensities decreased 24h after domoic acid injection in CA3 with APE and Ogg1 as well as in the Str. radiatum and Str. lacunosum-moleculare with StarD6 and APE. These results suggested that StarD6 may not be closely related with DNA repair proteins in the hippocampus after domoic acid-induced excitotoxicity, although the activities of these proteins might be positively affected by excitotoxic stimuli.
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Tiedeken JA, Ramsdell JS. Persistent Neurological Damage Associated With Spontaneous Recurrent Seizures and Atypical Aggressive Behavior of Domoic Acid Epileptic Disease. Toxicol Sci 2013; 133:133-43. [DOI: 10.1093/toxsci/kft037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Baron AW, Rushton SP, Rens N, Morris CM, Blain PG, Judge SJ. Sex differences in effects of low level domoic acid exposure. Neurotoxicology 2013; 34:1-8. [PMID: 23099319 DOI: 10.1016/j.neuro.2012.10.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 10/04/2012] [Accepted: 10/15/2012] [Indexed: 11/18/2022]
Abstract
Consumption of seafood containing the phytoplankton-derived toxin domoic acid (DOM) causes neurotoxicity in humans and in animals. It has been reported that DOM-induced symptoms may be more severe in men than women, but to date the effect of sex on DOM-induced effects in adults is not known. We investigated sex differences in DOM-induced effects in adult rats. Since low level exposure is of greatest relevance to human health (due to DOM regulatory limit), we examined the effects of low level exposure. Adult male and female Sprague Dawley rats were administered a single intraperitoneal injection of DOM (0, 1.0, 1.8 mg/kg). Behaviour was monitored for 3h and immunohistochemistry in the dorsal hippocampus and olfactory bulb was also examined. DOM increased locomotor and grooming activity, compared to vehicle group. DOM exposure also significantly increased stereotypic behaviours and decreased phosphorylated cAMP response element-binding protein immunoreactivity (pCREB-IR). There was no effect of sex on the magnitude of the behavioural responses, but the onset of DOM-induced locomotor activity and ear scratches was quicker in females than in males. Mixed effect modelling revealed the predicted peak in locomotor activity in response to DOM was also quicker in females than in males. Severe toxicity was evident in 2/7 male rats and 0/8 female rats dosed with 1.8 mg/kg DOM. These data suggest that males exposed to low level DOM may be more susceptible to severe neurotoxicity, whereas females are affected more quickly. Understanding sex differences in DOM-induced neurotoxicity may contribute to future protective strategies and treatments.
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Affiliation(s)
- Andrew W Baron
- Medical Toxicology Centre, Newcastle University, Newcastle upon Tyne NE2 4AA, UK.
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17
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Tiedeken JA, Muha N, Ramsdell JS. A Cupric Silver Histochemical Analysis of Domoic Acid Damage to Olfactory Pathways Following Status Epilepticus in a Rat Model for Chronic Recurrent Spontaneous Seizures and Aggressive Behavior. Toxicol Pathol 2012; 41:454-69. [DOI: 10.1177/0192623312453521] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The amnesic shellfish toxin, domoic acid, interferes with glutamatergic pathways leading to neuronal damage, most notably causing memory loss and seizures. In this study, the authors utilized a recently developed rat model for domoic acid–induced epilepsy, an emerging disease appearing in California sea lions weeks to months after poisoning, to identify structural damage that may lead to a permanent epileptic state. Sprague Dawley rats were kindled with several low hourly intraperitoneal doses of domoic acid until a state of status epilepticus (SE) appears. This kindling approach has previously been shown to induce a permanent state of epileptic disease in 96% animals within 6 months. Three animals were selected for neurohistology a week after the initial SE. An amino cupric silver staining method using neutral red counterstain was used on every eighth 40 µm coronal section from each brain to highlight neural degeneration from the olfactory bulb through the brain stem. The most extensive damage was found in the olfactory bulb and related olfactory pathways, including the anterior/medial olfactory cortices, endopiriform nucleus, and entorhinal cortex. These findings indicate that damage to olfactory pathways is prominent in a rat model for domoic acid–induced chronic recurrent spontaneous seizures and aggressive behavior.
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Affiliation(s)
- Jessica A. Tiedeken
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Ocean Service, Charleston, South Carolina, USA
| | - Noah Muha
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Ocean Service, Charleston, South Carolina, USA
| | - John S. Ramsdell
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Ocean Service, Charleston, South Carolina, USA
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18
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Hankir MK, Parkinson JR, Bloom SR, Bell JD. The effects of glutamate receptor agonists and antagonists on mouse hypothalamic and hippocampal neuronal activity shown through manganese enhanced MRI. Neuroimage 2011; 59:968-78. [PMID: 21925279 DOI: 10.1016/j.neuroimage.2011.08.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/05/2011] [Accepted: 08/21/2011] [Indexed: 11/17/2022] Open
Abstract
Manganese enhanced MRI (MEMRI) is an imaging paradigm that can be used to assess neuronal activity in vivo. Here we investigate, through the use of MEMRI, the influence of receptor dynamics on neuronal activity in the hypothalamus and hippocampus focusing on the glutamate receptor signalling system. We demonstrate that intraperitoneal (i.p.) administration of monosodium glutamate (MSG) and the ionotropic glutamate receptor (iGluR) agonists NMDA and AMPA resulted in significantly increased signal intensity (SI) in the arcuate nucleus (ARC), the suprachiasmatic nucleus (SCN) and the CA3 region of the hippocampus of mice consistent with increased neuronal activity. Administration of the NMDA receptor antagonist MK-801 resulted in significantly decreased SI in the paraventricular nucleus (PVN) consistent with decreased neuronal activity. Co-administration of MSG and the AMPA receptor antagonist NBQX attenuated the increase in SI observed in the ARC from MSG alone, suggesting MEMRI may be applicable to the study of receptor dynamics in vivo. We also observed that administration of the various iGluR agonists and antagonists modulated SI in the lateral ventricle and that high dose MSG (300 mg) caused a hitherto unseen enhancement in SI in the entire cortical/subarachnoid region. In conclusion, MEMRI reveals changes in neuronal activity in response to iGluR agonists and antagonists in the CNS in vivo as well as revealing multifaceted effects beyond those attributable to neuronal activity alone.
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Affiliation(s)
- Mohammed K Hankir
- Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, 3rd Floor Cyclotron Building, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK.
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19
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Rao DB, Little PB, Malarkey DE, Herbert RA, Sills RC. Histopathological evaluation of the nervous system in National Toxicology Program rodent studies: a modified approach. Toxicol Pathol 2011; 39:463-70. [PMID: 21430177 DOI: 10.1177/0192623311401044] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This article outlines the changes and underlying rationale for modifications to the histopathological evaluation of the nervous system during toxicology and carcinogenesis studies conducted by the National Toxicology Program (NTP). In the past, routine evaluation of the nervous system was mostly limited to three sections of brain, and occasionally the spinal cord and peripheral nerves. Factors such as the increasing occurrence of human neurological diseases and associated economical cost burden, the role of unidentified environmental stressors in neurodegenerative disorders, multiple therapeutic drug-induced neuropathies noted in human clinical trials, and the exponential use of environmental chemicals with unknown neurotoxic potential necessitate a more extensive evaluation of the nervous system. The NTP has modified its protocol to include examination of key anatomic subsites related to neurodegenerative diseases such as Parkinson's disease. Modifications include four additional sections of the brain. Increasing the number of brain sections permits examination of a greater number of specific anatomic subsites with unique vulnerability. In addition, the spinal cord, peripheral nerves, trigeminal ganglion, and intestinal autonomic ganglia will be evaluated as needed. It is expected that this modified approach will increase the sensitivity of detecting neurotoxicants and neurocarcinogens important in human neurologic and neurodegenerative disorders.
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Affiliation(s)
- Deepa B Rao
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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20
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Cook P, Reichmuth C, Gulland F. Rapid behavioural diagnosis of domoic acid toxicosis in California sea lions. Biol Lett 2011; 7:536-8. [PMID: 21389016 DOI: 10.1098/rsbl.2011.0127] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Domoic acid is a neurotoxic metabolite of widely occurring algal blooms that has caused multiple marine animal stranding events. Exposure to high doses of domoic acid, a glutamate agonist, may lead to persistent medial temporal seizures and damage to the hippocampus. California sea lions (Zalophus californianus) are among the most visible and frequent mammalian victims of domoic acid poisoning, but rapid, reliable diagnosis in a clinical setting has proved difficult owing to the fast clearance of the toxin from the blood stream. Here, we show that the behavioural orienting responses of stranded sea lions diagnosed with domoic acid toxicosis habituate more slowly to a series of non-aversive auditory stimuli than do those of sea lions with no apparent neurological deficits. A signal detection analysis based on these habituation measures was able to correctly identify 50 per cent of subjects with domoic acid toxicosis while correctly rejecting approximately 93 per cent of controls, suggesting potential diagnostic merit.
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Affiliation(s)
- Peter Cook
- Department of Cognitive Psychology, University of California Santa Cruz, CA 95060, USA.
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21
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Switzer RC, Lowry-Franssen C, Benkovic SA. Recommended Neuroanatomical Sampling Practices for Comprehensive Brain Evaluation in Nonclinical Safety Studies. Toxicol Pathol 2011; 39:73-84. [DOI: 10.1177/0192623310397557] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adequate tissue sampling is known to reduce the likelihood that the toxicity of novel biomolecules, chemicals, and drugs might go undetected. Each organ, and often specific structurally and functionally distinct regions within it, must be assessed to detect potential site-specific toxicity. Adequate sampling of the brain requires particular consideration because of the many major substructures and more than 600 subpopulations of generally irreplaceable cells with unique functions and vulnerabilities. All known neurotoxicants affect specific subpopulations (usually neurons) rather than damaging a certain percentage of cells throughout the brain; thus, all populations should be independently assessed for lesions. Historically, the affected neural cell subpopulation has not been predictable, but it is now clear that sampling selected populations (e.g., cerebral cortex, hippocampus, cerebellar folia) cannot forecast the health of other populations. This article reviews the neuroanatomical domains affected by several model neurotoxicants to illustrate the need for more comprehensive neurohistological evaluation during nonclinical development of novel compounds. The article also describes an easily executed, cost-effective method that uses a set number of evenly spaced coronal (cross) sections to accomplish this comprehensive brain assessment during nonclinical safety studies performed in rodents, dogs, and nonhuman primates.
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Affiliation(s)
| | - Catherine Lowry-Franssen
- NeuroScience Associates, Knoxville, Tennessee, USA
- Randolph-Macon College, Ashland, Virginia, USA
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22
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Watanabe KH, Andersen ME, Basu N, Carvan MJ, Crofton KM, King KA, Suñol C, Tiffany-Castiglioni E, Schultz IR. Defining and modeling known adverse outcome pathways: Domoic acid and neuronal signaling as a case study. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:9-21. [PMID: 20963854 DOI: 10.1002/etc.373] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
An adverse outcome pathway (AOP) is a sequence of key events from a molecular-level initiating event and an ensuing cascade of steps to an adverse outcome with population-level significance. To implement a predictive strategy for ecotoxicology, the multiscale nature of an AOP requires computational models to link salient processes (e.g., in chemical uptake, toxicokinetics, toxicodynamics, and population dynamics). A case study with domoic acid was used to demonstrate strategies and enable generic recommendations for developing computational models in an effort to move toward a toxicity testing paradigm focused on toxicity pathway perturbations applicable to ecological risk assessment. Domoic acid, an algal toxin with adverse effects on both wildlife and humans, is a potent agonist for kainate receptors (ionotropic glutamate receptors whose activation leads to the influx of Na(+) and Ca²(+)). Increased Ca²(+) concentrations result in neuronal excitotoxicity and cell death, primarily in the hippocampus, which produces seizures, impairs learning and memory, and alters behavior in some species. Altered neuronal Ca²(+) is a key process in domoic acid toxicity, which can be evaluated in vitro. Furthermore, results of these assays would be amenable to mechanistic modeling for identifying domoic acid concentrations and Ca²(+) perturbations that are normal, adaptive, or clearly toxic. In vitro assays with outputs amenable to measurement in exposed populations can link in vitro to in vivo conditions, and toxicokinetic information will aid in linking in vitro results to the individual organism. Development of an AOP required an iterative process with three important outcomes: a critically reviewed, stressor-specific AOP; identification of key processes suitable for evaluation with in vitro assays; and strategies for model development.
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Ryan JC, Cross CA, Van Dolah FM. Effects of COX inhibitors on neurodegeneration and survival in mice exposed to the marine neurotoxin domoic acid. Neurosci Lett 2011; 487:83-7. [DOI: 10.1016/j.neulet.2010.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 02/02/2023]
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Costa LG, Giordano G, Faustman EM. Domoic acid as a developmental neurotoxin. Neurotoxicology 2010; 31:409-23. [PMID: 20471419 PMCID: PMC2934754 DOI: 10.1016/j.neuro.2010.05.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/04/2010] [Accepted: 05/05/2010] [Indexed: 11/21/2022]
Abstract
Domoic acid (DomA) is an excitatory amino acid which can accumulate in shellfish and finfish under certain environmental conditions. DomA is a potent neurotoxin. In humans and in non-human primates, oral exposure to a few mg/kg DomA elicits gastrointestinal effects, while slightly higher doses cause neurological symptoms, seizures, memory impairment, and limbic system degeneration. In rodents, which appear to be less sensitive than humans or non-human primates, oral doses cause behavioral abnormalities (e.g. hindlimb scratching), followed by seizures and hippocampal degeneration. Similar effects are also seen in other species (from sea lions to zebrafish), indicating that DomA exerts similar neurotoxic effects across species. The neurotoxicity of DomA is ascribed to its ability to interact and activate the AMPA/KA receptors, a subfamily of receptors for the neuroexcitatory neurotransmitter glutamate. Studies exploring the neurotoxic effects of DomA on the developing nervous system indicate that DomA elicits similar behavioral, biochemical and morphological effects as in adult animals. However, most importantly, developmental neurotoxicity is seen at doses of DomA that are one to two orders of magnitude lower than those exerting neurotoxicity in adults. This difference may be due to toxicokinetic and/or toxicodynamic differences. Estimated safe doses may be exceeded in adults by high consumption of shellfish contaminated with DomA at the current limit of 20 microg/g. Given the potential higher susceptibility of the young to DomA neurotoxicity, additional studies investigating exposure to, and effects of this neurotoxin during brain development are warranted.
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Affiliation(s)
- Lucio G Costa
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA.
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25
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Ryan JC, Morey JS, Bottein MYD, Ramsdell JS, Van Dolah FM. Gene expression profiling in brain of mice exposed to the marine neurotoxin ciguatoxin reveals an acute anti-inflammatory, neuroprotective response. BMC Neurosci 2010; 11:107. [PMID: 20796285 PMCID: PMC2939656 DOI: 10.1186/1471-2202-11-107] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 08/26/2010] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Ciguatoxins (CTXs) are polyether marine neurotoxins and potent activators of voltage-gated sodium channels. This toxin is carried by multiple reef-fish species and human consumption of ciguatoxins can result in an explosive gastrointestinal/neurologic illness. This study characterizes the global transcriptional response in mouse brain to a symptomatic dose of the highly toxic Pacific ciguatoxin P-CTX-1 and additionally compares this data to transcriptional profiles from liver and whole blood examined previously. Adult male C57/BL6 mice were injected with 0.26 ng/g P-CTX-1 while controls received only vehicle. Animals were sacrificed at 1, 4 and 24 hrs and transcriptional profiling was performed on brain RNA with Agilent whole genome microarrays. RT-PCR was used to independently validate gene expression and the web tool DAVID was used to analyze gene ontology (GO) and molecular pathway enrichment of the gene expression data. RESULTS A pronounced 4°C hypothermic response was recorded in these mice, reaching a minimum at 1 hr and lasting for 8 hrs post toxin exposure. Ratio expression data were filtered by intensity, fold change and p-value, with the resulting data used for time course analysis, K-means clustering, ontology classification and KEGG pathway enrichment. Top GO hits for this gene set included acute phase response and mono-oxygenase activity. Molecular pathway analysis showed enrichment for complement/coagulation cascades and metabolism of xenobiotics. Many immediate early genes such as Fos, Jun and Early Growth Response isoforms were down-regulated although others associated with stress such as glucocorticoid responsive genes were up-regulated. Real time PCR confirmation was performed on 22 differentially expressed genes with a correlation of 0.9 (Spearman's Rho, p < 0.0001) with microarray results. CONCLUSIONS Many of the genes differentially expressed in this study, in parallel with the hypothermia, figure prominently in protection against neuroinflammation. Pathologic activity of the complement/coagulation cascade has been shown in patients suffering from a chronic form of ciguatera poisoning and is of particular interest in this model. Anti-inflammatory processes were at work not only in the brain but were also seen in whole blood and liver of these animals, creating a systemic anti-inflammatory environment to protect against the initial cellular damage caused by the toxin.
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Affiliation(s)
- James C Ryan
- Marine Biotoxins Program, NOAA Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, USA
| | - Jeanine S Morey
- Marine Biotoxins Program, NOAA Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, USA
| | | | - John S Ramsdell
- Marine Biotoxins Program, NOAA Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, USA
| | - Frances M Van Dolah
- Marine Biotoxins Program, NOAA Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, USA
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26
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Lefebvre KA, Robertson A. Domoic acid and human exposure risks: A review. Toxicon 2010; 56:218-30. [DOI: 10.1016/j.toxicon.2009.05.034] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 05/06/2009] [Accepted: 05/13/2009] [Indexed: 01/20/2023]
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Kostrzewa RM. Evolution of neurotoxins: from research modalities to clinical realities. ACTA ACUST UNITED AC 2009; Chapter 1:Unit 1.18. [PMID: 19170022 DOI: 10.1002/0471142301.ns0118s46] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In the 1950s, the discovery of anti-nerve growth factor, an immunotoxin stunting sympathetic neural development, signaled the advent of neurotoxins as research modalities. Other selective neurotoxins were discovered in rapid succession. In the 1960s, 6-hydroxydopamine and 6-hydroxydopa were shown to destroy noradrenergic and dopaminergic nerves. Excitotoxins (glutamate, aspartate, and analogs) were discovered in the 1970s. DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine] proved to be selective for noradrenergic destruction, while 5,6- and 5,7-dihydroxytryptamines were relatively selective for serotonin neurons. Additional neurotoxins were discovered, but it was MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) that predominated neurotoxicity research in the 1980s. Eventually, Clostridium botulinum neurotoxin (BoNT), discovered as a "poisonous" principle in the late 1800s, resurfaced in purified and standardized forms as a clinically useful drug. Neurotoxins represent chemical tools, useful not only for discerning neuronal mechanisms and animal modeling of neurological disorders, but also for their use in medicine and potential as treatments for medical disorders. This unit reviews the early discovery of neurotoxins, describes categories of neurotoxins, and finally characterizes their usefulness--first as research tools, and eventually as clinical therapeutic agents.
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Affiliation(s)
- Richard M Kostrzewa
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
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28
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Temporal neuropathologic and behavioral phenotype of 6neo/6neo Pompe disease mice. J Neuropathol Exp Neurol 2008; 67:803-18. [PMID: 18648322 DOI: 10.1097/nen.0b013e3181815994] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Pompe disease (glycogen storage disease II) is caused by mutations in the acid alpha-glucosidase gene. The most common form is rapidly progressive with glycogen storage, particularly in muscle, which leads to profound weakness, cardiac failure, and death by the age of 2 years. Although usually considered a muscle disease, glycogen storage also occurs in the CNS. We evaluated the progression of neuropathologic and behavioral abnormalities in a Pompe disease mouse model (6neo/6neo) that displays many features of the human disease. Homozygous mutant mice store excess glycogen within large neurons of hindbrain, spinal cord, and sensory ganglia by the age of 1 month; accumulations then spread progressively within many CNS cell types. "Silver degeneration" and Fluoro-Jade C stains revealed severe degeneration in axon terminals of primary sensory neurons at 3 to 9 months. These abnormalities were accompanied by progressive behavioral impairment on rotorod, wire hanging, and foot fault tests. The extensive neuropathologic alterations in this model suggest that therapy of skeletal and cardiac muscle disorders by systemic enzyme replacement therapy may not be sufficient to reverse functional deficits due to CNS glycogen storage, particularly early-onset, rapidly progressive disease. A better understanding of the basis for clinical manifestations is needed to correlate CNS pathology with Pompe disease manifestations.
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Domoic acid toxicologic pathology: a review. Mar Drugs 2008; 6:180-219. [PMID: 18728725 PMCID: PMC2525487 DOI: 10.3390/md20080010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 05/16/2008] [Accepted: 05/16/2008] [Indexed: 12/29/2022] Open
Abstract
Domoic acid was identified as the toxin responsible for an outbreak of human poisoning that occurred in Canada in 1987 following consumption of contaminated blue mussels [Mytilus edulis]. The poisoning was characterized by a constellation of clinical symptoms and signs. Among the most prominent features described was memory impairment which led to the name Amnesic Shellfish Poisoning [ASP]. Domoic acid is produced by certain marine organisms, such as the red alga Chondria armata and planktonic diatom of the genus Pseudo-nitzschia. Since 1987, monitoring programs have been successful in preventing other human incidents of ASP. However, there are documented cases of domoic acid intoxication in wild animals and outbreaks of coastal water contamination in many regions world-wide. Hence domoic acid continues to pose a global risk to the health and safety of humans and wildlife. Several mechanisms have been implicated as mediators for the effects of domoic acid. Of particular importance is the role played by glutamate receptors as mediators of excitatory neurotransmission and the demonstration of a wide distribution of these receptors outside the central nervous system, prompting the attention to other tissues as potential target sites. The aim of this document is to provide a comprehensive review of ASP, DOM induced pathology including ultrastructural changes associated to subchronic oral exposure, and discussion of key proposed mechanisms of cell/tissue injury involved in DOM induced brain pathology and considerations relevant to food safety and human health.
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Bakke MJ, Horsberg TE. Effects of algal-produced neurotoxins on metabolic activity in telencephalon, optic tectum and cerebellum of Atlantic salmon (Salmo salar). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2007; 85:96-103. [PMID: 17870190 DOI: 10.1016/j.aquatox.2007.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/07/2007] [Accepted: 08/08/2007] [Indexed: 05/17/2023]
Abstract
Neurotoxins from algal blooms have been reported to cause mortality in a variety of species, including sea birds, sea mammals and fish. Farmed fish cannot escape harmful algal blooms and their potential toxins, thus they are more vulnerable for exposure than wild stocks. Sublethal doses of the toxins are likely to affect fish behaviour and may impair cognitive abilities. In the present study, changes in the metabolic activity in different parts of the Atlantic salmon (Salmo salar) brain involved in central integration and cognition were investigated after exposure to sublethal doses of three algal-produced neurotoxins; saxitoxin (STX), brevetoxin (BTX) and domoic acid (DA). Fish were randomly selected to four groups for i.p. injection of saline (control) or one of the neurotoxins STX (10 microg STX/kg bw), BTX (68 microg BTX/kg bw) or DA (6 mg DA/kg bw). In addition, 14C-2-deoxyglucose was i.m. injected to measure brain metabolic activity by autoradiography. The three regions investigated were telencephalon (Tel), optic tectum (OT) and cerebellum (Ce). There were no differences in the metabolic activity after STX and BTX exposure compared to the control in these regions. However, a clear increase was observed after DA exposure. When the subregions with the highest metabolic rate were pseudocoloured in the three brain regions, the three toxins caused distinct differences in the respective patterns of metabolic activation. Fish exposed to STX displayed similar patterns as the control fish, whereas fish exposed to BTX and DA showed highest metabolic activity in subregions different from the control group. All three neurotoxins affected subregions that are believed to be involved in cognitive abilities in fish.
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Affiliation(s)
- Marit Jørgensen Bakke
- Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway
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Tiedeken JA, Ramsdell JS. Embryonic exposure to domoic Acid increases the susceptibility of zebrafish larvae to the chemical convulsant pentylenetetrazole. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:1547-52. [PMID: 18007982 PMCID: PMC2072828 DOI: 10.1289/ehp.10344] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Accepted: 08/02/2007] [Indexed: 05/20/2023]
Abstract
BACKGROUND Domoic acid (DA) is a neurotoxin produced by diatoms of the genus Pseudo-nitzschia that targets the limbic system to induce tonic-clonic seizures and memory impairment. In utero DA exposure of mice leads to a reduction in seizure threshold to subsequent DA exposures in mid-postnatal life, and similar studies have shown neurotoxic effects in rats that were delayed until adolescence. OBJECTIVE We used in ovo microinjection of zebrafish (Danio rerio) to characterize the effect of embryonic exposure of DA on seizure-inducing agents later in life as an alternative species model to screen environmental contaminants that might induce a fetal-originating adult disease. METHODS Embryos were microinjected within hours of fertilization to DA concentrations ranging from 0.12 to 1.26 ng/mg egg weight. Seven days later, the larval animals were characterized for sensitivity to the chemical convulsant pentylenetetrazole (PTZ), an agent that is well-defined in laboratory rodents and, more recently, in zebrafish. RESULTS In ovo DA exposure, most significantly at 0.4 ng/mg, reduces the latency time until first PTZ seizure in larval fish and increases the severity of seizures as determined by seizure stage and movement parameters. The interaction between in ovo DA exposure and PTZ caused seizure behaviors to individually asymptomatic doses of PTZ (1.0 and 1.25 mM) and DA (0.13 and 0.22 ng/mg). CONCLUSION These studies demonstrate that in ovo exposure to DA reduces the threshold to chemically induced seizures in larval fish and increases the severity of seizure behavior in a manner that is consistent with in utero studies of laboratory rodents.
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Affiliation(s)
| | - John S. Ramsdell
- Address correspondence to J.S. Ramsdell, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Rd., Charleston, SC 29412 USA. Telephone: (843) 762-8910. Fax: (843) 762-8700. E-mail:
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Tiedeken JA, Ramsdell JS, Ramsdell AF. Developmental toxicity of domoic acid in zebrafish (Danio rerio). Neurotoxicol Teratol 2005; 27:711-7. [PMID: 16061356 DOI: 10.1016/j.ntt.2005.06.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 05/12/2005] [Indexed: 10/25/2022]
Abstract
Domoic acid (DA) is a rigid analog of the excitatory amino acid glutamate. It is produced by the diatom genus Pseudo-nitzschia and is a potent neurotoxin in both adult and developing animals. We have used zebrafish (Danio rerio) as a model to investigate and characterize the developmental toxicity of DA. Domoic acid was administered by microinjection to fertilized eggs at the 128- to 512-cell stages in concentrations ranging from 0.12 to 17 mg/kg (DA/egg weight). DA reduced hatching success by 40% at 0.4 mg/kg and by more than 50% at doses of 1.2 mg/kg and higher. Fifty percent of embryos treated with 1.2 mg/kg DA showed marked tonic-clonic type convulsions at 2 days post fertilization. Four days post fertilization (dpf), all embryos treated with 4.0 mg/kg DA and higher showed a complete absence of touch response reflexes. Commencing 5 dpf, rapid and constant pectoral fin movements were observed, a response which may be related to the hallmark effect in rodents of stereotypic scratching. These data indicate that zebrafish show symptoms of developmental DA toxicity as well as a similar sensitivity comparable to the effects of DA characterized in laboratory rodents.
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Affiliation(s)
- Jessica A Tiedeken
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, NOAA, National Ocean Service, 219 Fort Johnson Rd., Charleston, SC 29412, USA
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