{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,3]],"date-time":"2026-09-03T16:58:58Z","timestamp":1788454738856,"version":"build-2803163510"},"reference-count":41,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,3,29]],"date-time":"2022-03-29T00:00:00Z","timestamp":1648512000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Methylmercury (MeHg) is one of the most dangerous toxic pollutants spread throughout the earth. Chronic MeHg intoxication by contaminated food ingestion is the most common threat to human health, including impairment to the developing fetus. The present study aims at investigating the effects of maternal exposure to MeHg during gestation and lactation on the spinal cord of offspring. Pregnant rats received oral doses of MeHg (40 \u03bcg\/kg\/day) over a period of 42 days (21 gestation and 21 lactation). Control animals received the vehicle only. Total mercury concentration was measured in blood samples from offspring collected at the 41st postnatal day. Counting of motor neurons and immunoreactivity for myelin basic protein (MBP) were assessed in the spinal cords in both control and MeHg-intoxicated animals. Our results showed that MeHg promoted an increase in blood Hg levels. In addition, it caused a reduction in the number of spinal cord motor neurons as well as decreased MBP immunoreactivity in the cervical, thoracic and lumbar segments. Our present findings suggest that MeHg intoxication during rat pregnancy and lactation is associated with a pattern of motor neuron degeneration and downregulation of myelin basic protein in different segments of a developing spinal cord. Further studies are needed to establish the effect of MeHg intoxication in both young and adult rats.<\/jats:p>","DOI":"10.3390\/ijms23073777","type":"journal-article","created":{"date-parts":[[2022,3,29]],"date-time":"2022-03-29T21:44:52Z","timestamp":1648590292000},"page":"3777","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Methylmercury Causes Neurodegeneration and Downregulation of Myelin Basic Protein in the Spinal Cord of Offspring Rats after Maternal Exposure"],"prefix":"10.3390","volume":"23","author":[{"given":"Diane Cleydes Ba\u00eda","family":"da Silva","sequence":"first","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonardo Oliveira","family":"Bittencourt","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7133-6391","authenticated-orcid":false,"given":"Daiane Claydes","family":"Baia-da-Silva","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victoria Santos","family":"Chemelo","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luciana","family":"Eir\u00f3-Quirino","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4949-2870","authenticated-orcid":false,"given":"Priscila Cunha","family":"Nascimento","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u00e1rcia Cristina Freitas","family":"Silva","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6483-0498","authenticated-orcid":false,"given":"Marco Aurelio M.","family":"Freire","sequence":"additional","affiliation":[{"name":"Graduate Program in Health and Society, University of the State of Rio Grande do Norte, Mossor\u00f3 59610-210, RN, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Walace","family":"Gomes-Leal","sequence":"additional","affiliation":[{"name":"Laboratory of Experimental Neuroprotection and Neuroregeneration, Unity of Morphophysiology, Federal University of Western Par\u00e1, Santar\u00e9m 68040-470, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1335-6853","authenticated-orcid":false,"given":"Maria Elena","family":"Crespo-Lopez","sequence":"additional","affiliation":[{"name":"Laboratory of Molecular Pharmacology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1486-4013","authenticated-orcid":false,"given":"Rafael Rodrigues","family":"Lima","sequence":"additional","affiliation":[{"name":"Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Par\u00e1, Bel\u00e9m 66075-110, PA, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,29]]},"reference":[{"key":"ref_1","unstructured":"(2021, November 18). UNEP United Nations Environment Program. Available online: https:\/\/www.unenvironment.org\/resources\/publication\/global-mercury-assessment-2018."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"106223","DOI":"10.1016\/j.envint.2020.106223","article-title":"Mercury: What can we learn from the Amazon?","volume":"146","author":"Macchi","year":"2021","journal-title":"Environ. Int."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Langeland, A.L., Hardin, R.D., and Neitzel, R.L. (2017). Mercury levels in human hair and farmed fish near artisanal and small-scale gold mining communities in the Madre de Dios river basin, Peru. Int. J. Environ. Res. Public Health, 14.","DOI":"10.20944\/preprints201703.0076.v1"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Vega, C.M., Orellana, J.D.Y., Oliveira, M.W., Hacon, S.S., and Basta, P.C. (2018). Human mercury exposure in Yanomami indigenous villages from the Brazilian Amazon. Int. J. Environ. Res. Public Health, 15.","DOI":"10.3390\/ijerph15061051"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.phrs.2009.02.011","article-title":"Mercury and human genotoxicity: Critical considerations and possible molecular mechanisms","volume":"60","author":"Pereira","year":"2009","journal-title":"Pharmacol. Res."},{"key":"ref_6","first-page":"7466","article-title":"Comparative study of mercury speciation in commercial fishes of the Brazilian Amazon","volume":"21","author":"Arrifano","year":"2014","journal-title":"Environ. Sci. Pollut. Res. Int."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Ruggieri, F., Majorani, C., Domanico, F., and Alimonti, A. (2017). Mercury in Children: Current State on Exposure through Human Biomonitoring Studies. Int. J. Environ. Res. Public Health, 14.","DOI":"10.3390\/ijerph14050519"},{"key":"ref_8","unstructured":"Watson, C., Paxinos, G., and Kayalioglu, G. (2009). The Spinal Cord. A Christopher and Dana Reeve Foundation Text and Atlas, Elsevier. [1st ed.]."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.ncl.2012.09.009","article-title":"The spinal cord: A review of functional neuroanatomy","volume":"31","author":"Bican","year":"2013","journal-title":"Neurol. Clin."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.jtemb.2018.09.004","article-title":"Low doses of methylmercury exposure during adulthood in rats display oxidative stress, neurodegeneration in the motor cortex and lead to impairment of motor skills","volume":"51","author":"Santana","year":"2019","journal-title":"J. Trace Elem. Med. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1111\/joim.12045","article-title":"Long-lasting neurotoxic effects of exposure to methylmercury during development","volume":"273","author":"Ceccatelli","year":"2013","journal-title":"J. Intern. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.neuro.2020.07.007","article-title":"Developmental exposure to methylmercury and resultant muscle mercury accumulation and adult motor deficits in mice","volume":"81","author":"Rand","year":"2020","journal-title":"Neurotoxicology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/S0006-8993(02)02964-5","article-title":"Evaluation of changes in methylmercury accumulation in the developing rat brain and its effects: A study with consecutive and moderate dose exposure throughout gestation and lactation periods","volume":"949","author":"Sakamoto","year":"2002","journal-title":"Brain Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1007\/s40572-018-0185-0","article-title":"Environmental mechanisms of neurodevelopmental toxicity","volume":"5","author":"Rock","year":"2018","journal-title":"Curr. Environ. Health Rep."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.drugalcdep.2018.06.022","article-title":"Prenatal and concurrent cocaine, alcohol, marijuana, and tobacco effects on adolescent cognition and attention","volume":"191","author":"Singer","year":"2018","journal-title":"Drug Alcohol Depend."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"105188","DOI":"10.1016\/j.earlhumdev.2020.105188","article-title":"Prenatal opioid exposure\u2014Increasing evidence of harm","volume":"150","author":"Mactier","year":"2020","journal-title":"Early Hum. Dev."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.pneurobio.2013.04.001","article-title":"Brain development in rodents and humans: Identifying benchmarks of maturation and vulnerability to injury across species","volume":"106\u2013107","author":"Semple","year":"2013","journal-title":"Prog. Neurobiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"106201","DOI":"10.1016\/j.envint.2020.106201","article-title":"Prenatal and postnatal mercury exposure and blood pressure in childhood","volume":"146","author":"Farzan","year":"2021","journal-title":"Environ. Int."},{"key":"ref_19","first-page":"111686","article-title":"Human neurotoxicity of mercury in the Amazon: A scoping review with insights and critical considerations","volume":"15","author":"Arrifano","year":"2021","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.neuro.2006.06.007","article-title":"Differential effects of methylmercury intoxication in the rat\u2019s barrel field as evidenced by NADPH diaphorase histochemistry","volume":"28","author":"Freire","year":"2007","journal-title":"Neurotoxicology"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5653291","DOI":"10.1155\/2017\/5653291","article-title":"Oxidative biochemistry disbalance and changes on proteomic profile in salivary glands of rats induced by chronic exposure to methylmercury","volume":"2017","author":"Bittencourt","year":"2017","journal-title":"Oxid. Med. Cell Longev."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1039\/C8MT00297E","article-title":"Proteomic approach underlying the hippocampal neurodegeneration caused by low doses of methylmercury after long-term exposure in adult rats","volume":"11","author":"Bittencourt","year":"2019","journal-title":"Metallomics"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1016\/j.ecoenv.2019.03.009","article-title":"Methylmercury intoxication and cortical ischemia: Pre-clinical study of their comorbidity","volume":"15","author":"Freire","year":"2019","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"110799","DOI":"10.1016\/j.ecoenv.2020.110799","article-title":"Effects of methylmercury on the pattern of NADPH diaphorase expression and astrocytic activation in the rat","volume":"201","author":"Freire","year":"2020","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"111772","DOI":"10.1016\/j.fct.2020.111772","article-title":"Chronic methylmercury exposure causes spinal cord impairment: Proteomic modulation and oxidative stress","volume":"146","author":"Ferreira","year":"2020","journal-title":"Food Chem. Toxicol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3707","DOI":"10.1007\/s12011-020-02492-2","article-title":"Imaging microstructural damage and alveolar bone loss in rats systemically exposed to methylmercury: First experimental evidence","volume":"199","author":"Bittencourt","year":"2021","journal-title":"Biol. Trace Elem. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"126820","DOI":"10.1016\/j.jtemb.2021.126820","article-title":"Salivary parameters alterations after early exposure to environmental methylmercury: A preclinical study in offspring rats","volume":"68","author":"Nascimento","year":"2021","journal-title":"J. Trace Elem. Med. Biol."},{"key":"ref_28","first-page":"13","article-title":"Spinal cord functional anatomy","volume":"21","author":"Cho","year":"2015","journal-title":"Continuum"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"110159","DOI":"10.1016\/j.ecoenv.2019.110159","article-title":"Spinal cord neurodegeneration after inorganic mercury long-term exposure in adult rats: Ultrastructural, proteomic and biochemical damages associated with reduced neuronal density","volume":"191","author":"Bittencourt","year":"2020","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"110358","DOI":"10.1016\/j.ecoenv.2020.110358","article-title":"Long-term exposure to lead reduces antioxidant capacity and triggers motor neurons degeneration and demyelination in spinal cord of adult rats","volume":"194","author":"Bittencourt","year":"2020","journal-title":"Ecotoxicol. Environ. Saf."},{"key":"ref_31","unstructured":"Council, N.R. (2011). Guide for the Care and Use of Laboratory Animals, The National Academies Press. [8th ed.]."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1016\/j.neuro.2015.07.001","article-title":"The effects of methylmercury exposure on behavior and biomarkers of oxidative stress in adult mice","volume":"50","author":"Kirkpatrick","year":"2015","journal-title":"Neurotoxicology"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2983","DOI":"10.1007\/s12011-020-02409-z","article-title":"Methylmercury-induced toxicopathologic findings in salivary glands of offspring rats after gestational and lactational exposure","volume":"199","author":"Nascimento","year":"2021","journal-title":"Biol. Trace Elem. Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"5233","DOI":"10.1021\/pr400356v","article-title":"Chronic exposure of adult rats to low doses of methylmercury induced a state of metabolic deficit in the somatosensory cortex","volume":"12","author":"Kong","year":"2013","journal-title":"J. Proteome Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2992","DOI":"10.1007\/s12011-020-02411-5","article-title":"Long-term exposure to inorganic mercury leads to oxidative stress in peripheral blood of adult rats","volume":"199","author":"Chemelo","year":"2021","journal-title":"Biol. Trace Elem. Res."},{"key":"ref_36","first-page":"1021","article-title":"In search for a gold-standard procedure to count motor neurons in the spinal cord","volume":"33","author":"Ferrucci","year":"2018","journal-title":"Histol. Histopathol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1007\/s10753-007-9046-y","article-title":"Diffuse axonal damage, myelin impairment, astrocytosis and inflammatory response following microinjections of NMDA into the rat striatum","volume":"31","author":"Lima","year":"2008","journal-title":"Inflammation"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3173564","DOI":"10.1155\/2016\/3173564","article-title":"Neurodegeneration and glial response after acute striatal stroke: Histological basis for neuroprotective studies","volume":"2016","author":"Lima","year":"2016","journal-title":"Oxid. Med. Cell. Longev."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1945","DOI":"10.1007\/s00018-006-6094-7","article-title":"Myelin basic protein: A multifunctional protein","volume":"63","author":"Boggs","year":"2006","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.brainres.2010.05.041","article-title":"Expression of the immediate-early gene egr-1 and substance P in the spinal cord following locomotor training in adult rats","volume":"1345","author":"Nunes","year":"2010","journal-title":"Brain Res."},{"key":"ref_41","first-page":"1069","article-title":"Immunohistochemical changes and atrophy after chronic ethanol intoxication in rat salivary glands","volume":"30","author":"Fernandes","year":"2015","journal-title":"Histol. Histopathol."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/23\/7\/3777\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:46:05Z","timestamp":1760136365000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/23\/7\/3777"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,29]]},"references-count":41,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2022,4]]}},"alternative-id":["ijms23073777"],"URL":"https:\/\/doi.org\/10.3390\/ijms23073777","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,3,29]]}}}