Journal of Molecular Neuroscience

, Volume 66, Issue 2, pp 291–305 | Cite as

Continuous Exposure to Inorganic Mercury Affects Neurobehavioral and Physiological Parameters in Mice

  • Hafsa Malqui
  • Hammou Anarghou
  • Fatima Zahra Ouardi
  • Nabila Ouasmi
  • Mohamed Najimi
  • Fatiha ChigrEmail author


Contamination with mercury is a real health issue for humans with physiological consequences. The main objective of the present study was to assess the neurotoxicological effect of inorganic mercury: HgCl2. For this, adult mice were exposed prenatally, postnatally, and during the adult period to a low level of the metal, and their behavior and antioxidant status were analyzed. First, we showed that mercury concentrations in brain tissue of treated animals showed significant bioaccumulation, which resulted in behavioral deficits in adult mice. Thus, the treated mice developed an anxiogenic state, as evidenced by open field and elevated plus maze tests. This anxiety-like behavior was accompanied by a decrease in social behavior. Furthermore, an impairment of memory in these treated mice was detected in the object recognition and Y-maze tests. The enzymatic activity of the antioxidant system was assessed in eight brain structures, including the cerebral cortex, olfactory bulb, hippocampus, hypothalamus, mesencephalon, pons, cerebellum, and medulla oblongata. The results show that chronic exposure to HgCl2 caused alterations in the activity of catalase, thioredoxin reductase, glutathione peroxidase, superoxide dismutase, and glutathione S-transferase, accompanied by peroxidation of membrane lipids, indicating a disturbance in intracellular redox homeostasis with subsequent increased intracellular oxidative stress. These changes in oxidative stress were concomitant with a redistribution of essential heavy metals, i.e., iron, copper, zinc, and magnesium, in the brain as a possible response to homeostatic dysfunction following chronic exposure. The alterations observed in overall oxidative stress could constitute the basis of the anxiety-like state and the neurocognitive disorders observed.


Mercury Neurotoxicity Antioxidant system Neurobehavior Anxiety 


Author Contributions

HM, FC, and MN designed the experiments and performed the analysis of the data; HM, HA, NO, and FZO performed the experiments and assembled the figures. All the authors wrote or edited and validated the manuscript.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


  1. Abu Bakar N, Mohd Sata NS, Ramlan NF, Wan Ibrahim WN, Zulkifli SZ, Che Abdullah CA, Ahmad S, Amal MN (2017) Evaluation of the neurotoxic effects of chronic embryonic exposure with inorganic mercury on motor and anxiety-like responses in zebrafish (Danio rerio) larvae. Neurotoxicol Teratol 59:53–61. CrossRefPubMedGoogle Scholar
  2. Agarwal JR, Behari (2007) Role of selenium in mercury intoxication in mice. Ind Health 45(3):388–395. CrossRefPubMedGoogle Scholar
  3. Asada K, Takahashi M, Nagate M (1974) Assay and inhibitors of spinach superoxide dismutase. Agric Biol Chem 38:471–473. CrossRefGoogle Scholar
  4. Azevedo FB, Barros FL, Peçanha FM, Wiggers GA, Frizera VP, Ronacher SM, Fiorim J, Rossi de Batista P, Fioresi M, Rossoni L, Stefanon I, Alonso MJ, Salaices M, ValentimVassallo D (2012) Toxic effects of mercury on the cardiovascular and central nervous systems. J Biomed Biotechnol 949048:1–11. CrossRefGoogle Scholar
  5. Barregård L, Lindstedt G, Schütz A, Sällsten G (1994) Endocrine function in mercury exposed chloralkali workers. Occup Environ Med 51(8):536–540CrossRefGoogle Scholar
  6. Basha CD, Reddy RG (2015) Long-term changes in brain cholinergic system and behavior in rats following gestational exposure to lead: protective effect of calcium supplement. Interdiscip Toxicol 8:159–168. CrossRefPubMedPubMedCentralGoogle Scholar
  7. Bernohft RA (2012) Mercury toxicity and treatment: a review of the literature. J Environ Public Health 460508:1–10. CrossRefGoogle Scholar
  8. Berry A, Capone F, Giorgio M, Pelicci PG, de Kloet ER, Alleva E, Minghetti L, Cirulli F (2007) Deletion of the life span determinant p66Shc prevents age-dependent increases in emotionality and pain sensitivity in mice. Exp Gerontol 42:37–45. CrossRefPubMedGoogle Scholar
  9. Bhimte B, Agrawal BK, Sharma VK, Chauhan SS (2012) Oxidative stress status in hypothyroid patients. Biomed Res 23:286–288Google Scholar
  10. Blanchard RJ, Hebert MA, Ferrari PF, Palanza P, Figueira R, Blanchard DC, Parmigiani S (1998) Defensive behaviors in wild and laboratory (Swiss) mice: the mouse defense test battery. Physiol Behav 65:201–209CrossRefGoogle Scholar
  11. Bouayed J, Rammal H, Soulimani R (2009) Oxidative stress and anxiety. Oxidative Med Cell Longev 2:63–67 CrossRefGoogle Scholar
  12. Bramley GN, Wass JR (2001) Laboratory and field evaluation of predator odors as repellents for kiore (Rattus exulans) and ship rats (R. rattus). J Chem Ecol 27:1029–1047CrossRefGoogle Scholar
  13. Branco V, Canário J, Lu J, Holmgren A, Carvalho C (2012) Mercury and selenium interaction in vivo: effects on thioredoxin reductase and glutathione peroxidase. Free Radic Biol Med 52(4):781–793. CrossRefPubMedGoogle Scholar
  14. Buege JA, Aust SD (1984) Microsomal lipid peroxidation. Methods Enzymol 105:302–310Google Scholar
  15. Cernichiari E, Myers GJ, Ballatori N, Zareba G, Vyas J, Clarkson T (2007) The biological monitoring of prenatal exposure to methylmercury. Neurotoxicology 28:1015–1022. CrossRefPubMedGoogle Scholar
  16. Chehimi L, Roy V, Jeljeli M, Sakly M (2012) Chronic exposure to mercuric chloride during gestation affects sensorimotor development and later behaviour in rats. Behav Brain Res 234:43–50. CrossRefPubMedGoogle Scholar
  17. Clarkson TW, Magos L (2006) The toxicology of mercury and its chemical compounds. Crit Rev Toxicol 36:609–662. CrossRefPubMedGoogle Scholar
  18. Crawley JN (2004) Designing mouse behavioral tasks relevant to autistic-like behaviors. Ment Retard Dev Disabil Res Rev 10:248–258CrossRefGoogle Scholar
  19. Das M, Mukhtar H, Seth PK (1982) Aryl hydrocarbon hydroxylase and glutathione-S-transferase activities in discrete regions of rat brain. Toxicol Lett 13(1–2):125–128CrossRefGoogle Scholar
  20. Desrumaux C, Risold PY, Schroeder H, Deckert V, Masson D, Athias A, Laplanche H, Le Guern N, Blache D, Jiang XC, Tall AR, Desor D, Lagrost L (2005) Phospholipid transfer protein (PLTP) deficiency reduces brain vitamin E content and increases anxiety in mice. FASEB J 19:296–297. CrossRefPubMedGoogle Scholar
  21. Ekino S, Susa M, Ninomiya T, Imamura K, Kitamura T (2007) Minamata disease revisited: an update on the acute and chronic manifestations of methyl mercury poisoning. J Neurol Sci 262:131–144. CrossRefPubMedGoogle Scholar
  22. Ellman GL, Courtney KD, Andres V Jr, Feather-Stone RM (1961) A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem Pharmacol 7:88–95CrossRefGoogle Scholar
  23. Ennaceur A, Meliani K (1988) A new one-trial test for neurobiological studies of memory in rats III. Spatial vs. non-spatial working memory. Behav Brain Res 51(1):83–92CrossRefGoogle Scholar
  24. Falluel-Morel A, Sokolowski K, Sisti HM, Zhou X, Shors TJ, Dicicco-Bloom E (2007) Developmental mercury exposure elicits acute hippocampal cell death, reductions in neurogenesis, and severe learning deficits during puberty. J Neurochem 103(5):1968–1981. CrossRefPubMedPubMedCentralGoogle Scholar
  25. Falluel-Morel A, Lin L, Sokolowski K, McCandlish E, Buckley B, Dicicco-Bloom E (2012) N-acetyl cysteine (NAC) treatment reduces mercury-induced neurotoxicity in the developing rat hippocampus. J Neurosci Res 90:743–750. CrossRefPubMedPubMedCentralGoogle Scholar
  26. Feng W, Wang M, Li B, Liu J, Chai Z, Zhao J, Deng G (2004) Mercury and trace element distribution in organic tissues and regional brain of fetal rat after in utero and weaning exposure to low dose of inorganic mercury. Toxicol Lett 152(3):223–234. CrossRefPubMedGoogle Scholar
  27. Fischer S, Ehlert U (2018) Hypothalamic–pituitary–thyroid (HPT) axis functioning in anxiety disorders. A systematic review. Depress Anxiety 35(1):98–110. CrossRefPubMedGoogle Scholar
  28. Flohe L, Gunzler WA (1984) Analysis of glutathione peroxidase. Methods Enzymol 105:114–121CrossRefGoogle Scholar
  29. Franciscato C, Goulart FR, Lovatto NM, Duarte FA, Flores EM, Dressler VL, Peixoto NC, Pereira ME (2009) ZnCl2 exposure protects against behavioral and acetylcholinesterase changes induced by HgCl2. Int J Dev Neurosci 27:459–468. CrossRefPubMedGoogle Scholar
  30. Girardi G, Elías MM (1995) Mercuric chloride effects on rat renal redox enzymes activities: SOD protection. Free Radic Biol Med 18:61–66CrossRefGoogle Scholar
  31. Glickstein M, Strata P, Voog DJ (2009) Cerebellum: history. Neuroscience 162:549–559CrossRefGoogle Scholar
  32. Goel A, Dani V, Dhawan DK (2007) Zinc mediates normalization of hepatic drug metabolizing enzymes in chlorpyrifos-induced toxicity. Toxicol Lett 169:26–33. CrossRefPubMedGoogle Scholar
  33. Goulet S, Dore FY, Mirault ME (2003) Neurobehavioral changes in mice chronically exposed to methylmercury during fetal and early postnatal development. Neurotoxicol Teratol 25:335–347. CrossRefPubMedGoogle Scholar
  34. Gstraunthaler G, Pfaller W, Kotanko P (1983) Glutathione depletion and in vitro lipid peroxidation in mercury or maleate induced acute renal failure. Biochem Pharmacol 32:2969–2972CrossRefGoogle Scholar
  35. Hogg S (1996) A review of the validity and variability of the elevated plus-maze as an animal model of anxiety. Pharmacol Biochem Behav 54:21–30CrossRefGoogle Scholar
  36. Hovatta I, Tennant RS, Helton R, Marr RA, Singer O, Redwine JM, Ellison JA, Schadt EE, Verma IM, Lockhart DJ, Barlow C (2005) Glyoxalase 1 and glutathione reductase 1 regulate anxiety in mice. Nature 438:662–666CrossRefGoogle Scholar
  37. Huang CF, Liu SH, Hsu CJ, Lin-Shiau SY (2011) Neurotoxicological effects of low-dose methylmercury and mercuric chloride in developing offspring mice. Toxicol Lett 201:196–204. CrossRefPubMedGoogle Scholar
  38. Institóris L, Siroki O, Undeger U, Basaran N, Dési I (2001) Immunotoxicological investigations on rats treated subacutely with dimethoate, As3+ and Hg2+ in combination. Hum Exp Toxicol 20:329–336CrossRefGoogle Scholar
  39. Kang-Yum E, Oransky SH (1992) Chinese patent medicine as a potential source of mercury poisoning. Vet Hum Toxicol 34(3):235–238PubMedGoogle Scholar
  40. Karpathios T, Zervoudakis A, Theodoridis C, Vlachos P, Apostolopoulou E, Fretzayas A (1991) Mercury vapor poisoning associated with hyperthyroidism in a child. Acta Peadiatrica Scand 80:551–552. CrossRefGoogle Scholar
  41. Komosinska-Vassev K, Olczyk K, Kucharz EJ, Marcisz C, Winsz-Szczotka K, Kotulska A (2000) Free radical activity and antioxidant defense mechanisms in patients with hyperthyroidism due to Graves' disease during therapy. Clin Chim Acta 300:107–117CrossRefGoogle Scholar
  42. Liapi C, Zarros A, Galanopoulou P, Theocharis S, Skandali N, Al-Humadi H, Anifantaki F, Gkrouzman E, Mellios Z, Tsakiris S (2008) Effects of short-term exposure to manganese on the adult rat brain antioxidant status and the activities of acetylcholinesterase, (Na,K)-ATPase and Mg-ATPase: modulation by L-cysteine. Basic Clin Pharmacol Toxicol 103:171–175. CrossRefPubMedGoogle Scholar
  43. Lowry O, Rosebrough N, Farr A, Randall R (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275PubMedGoogle Scholar
  44. Maia C d S, Ferreira VM, Diniz JS, Carneiro FP, de Sousa JB, da Costa ET, Tomaz C (2010) Inhibitory avoidance acquisition in adult rats exposed to a combination of ethanol and methylmercury during central nervous system development. Behav Brain Res 211(2):191–197. CrossRefGoogle Scholar
  45. Mastripieri D, Martel FL, Nevison CM, Simpson MJA, Keverne EB (1992) Anxiety in rhesus monkey infants in relation to interactions with their mother and other social companions. Dev Psychobiol 24:571–581CrossRefGoogle Scholar
  46. Mello-Carpes PB, Barros W, Borges S, Alves N, Rizzetti D, Peçanha FM, Vassallo DV, Wiggers GA, Izquierdo I (2013) Chronic exposure to low mercury chloride concentration induces object recognition and aversive memories deficits in rats. Int J Dev Neurosci 31:468–472. CrossRefPubMedGoogle Scholar
  47. Milatovic D, Gupta RC, Aschner M (2006) Anticholinesterase toxicity and oxidative stress. Sci World J 6:295–310. CrossRefGoogle Scholar
  48. Nagahara AH, McGaugh JL (1992) Muscicimol infused into the medial septal area impairs long term memory but not short-term memory in inhibitory avoidance, water maze place learning and rewarded alternation tasks. Brain Res 591:54–61CrossRefGoogle Scholar
  49. Oliveira CS, Oliveira VA, Ineu RP, Moraes-Silva L, Pereira ME (2012) Biochemical parameters of pregnant rats and their offspring exposed to different doses of inorganic mercury in drinking water. Food Chem Toxicol 50:2382–2387. CrossRefPubMedGoogle Scholar
  50. Ornagh IF, Ferrini S, Prati M, Giavini E (1993) The protective effects of N-acetyl-L-cysteine against methylmercury embryotoxicity in mice. Fundam Appl Toxicol 20:437–445CrossRefGoogle Scholar
  51. Peixoto NC, Roza T, Morsch VM, Pereira ME (2007) Behavioral alterations induced by HgCl2 depend on the postnatal period of exposure. Int J Dev Neurosci 25:39–46. CrossRefPubMedGoogle Scholar
  52. Pellow S, Chopin P, File SE, Briley M (1985) Validation of open: closed arm entries in an elevated plus-maze as a measure of anxiety in the rat. J Neurosci Methods 14:149–167CrossRefGoogle Scholar
  53. Rico EP, Rosemberg DB, Dias RD, Bogo MR, Bonan CD (2007) Ethanol alters acetylcholinesterase activity and gene expression in zebrafish brain. Toxicol Lett 174(1–3):25–30. CrossRefPubMedGoogle Scholar
  54. Riley DM, Newby CA, Leal-Almeraz TO, Thomas VM (2001) Assessing elemental mercury vapor exposure from cultural and religious practices. Environ Health Perspect 109:779–784. CrossRefPubMedPubMedCentralGoogle Scholar
  55. Rodgers RJ, Cole JC (1994) The elevated plus-maze: pharmacology, methodology and ethology. In: Cooper SJ, Hendrie CA (eds) Ethology and psychopharmacology. Wiley, Chichester, pp 9–44Google Scholar
  56. Rudd JW, Furutani A, Turner MA (1980) Mercury methylation by fish intestinal contents. Appl Environ Microbiol 40:777–782PubMedPubMedCentralGoogle Scholar
  57. Ryan DM, Sin YM, Wong MK (1991) Uptake distribution and immunotoxicological effects of mercury in mice. Environ Monit Assess 19:507–517CrossRefGoogle Scholar
  58. Santos D, Milatovic D, Andrade V, Batoreu MC, Aschner M, Marreilha dos Santos AP (2012) The inhibitory effect of manganese on acetylcholinesterase activity enhances oxidative stress and neuroinflammation in the rat brain. Toxicology 292:90–98. CrossRefPubMedGoogle Scholar
  59. Schantz SL, Widholm JJ (2001) Cognitive effects of endocrine-disrupting chemicals in animals. Environ Health Perspect 109:1197–1206CrossRefGoogle Scholar
  60. Simon NM, Blacker D, Korbly NB, Sharma SG, Worthington JJ, Otto MW, Pollack MH (2002) Hypothyroidism and hyperthyroidism in anxiety disorders revisited: new data and literature review. J Affect Disord 69:209–217CrossRefGoogle Scholar
  61. Songur A, Sarsilmaz M, Sogut S, Ozyurt B, Ozyurt H, Zararsiz I, Turkoglu AO (2004) Hypothalamic superoxide dismutase, xanthine oxidase, nitric oxide, and malondialdehyde in rats fed with fish omega-3 fatty acids. Prog Neuro-Psychopharmacol Biol Psychiatry 28:693–698. CrossRefGoogle Scholar
  62. Souza CG, Moreira JD, Siqueira IR, Pereira AG, Rieger DK, Souza DO, Souza TM, Portela LV, Perry ML (2007) Highly palatable diet consumption increases protein oxidation in rat frontal cortex and anxiety-like behavior. Life Sci 81:198–203. CrossRefPubMedGoogle Scholar
  63. Spiller HA (2018) Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity. Clin Toxicol (Phila) 56:313–326. CrossRefGoogle Scholar
  64. Stringari J, Nunes AK, Franco JL, Bohrer D, Garcia SC, Dafre AL, Milatovic D, Souza DO, Rocha JB, Aschner M, Farina M (2008) Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain. Toxicol Appl Pharmacol 227:147–154. CrossRefPubMedGoogle Scholar
  65. Teixeira FB, Fernandes RM, Farias-Junior PM, Costa NM, Fernandes LM, Santana LN, Silva-Junior AF, Silva MC, Maia CS, Lima RR (2014) Evaluation of the effects of chronic intoxication with inorganic mercury on memory and motor control in rats. Int J Environ Res Public Health 11:9171–9185. CrossRefPubMedPubMedCentralGoogle Scholar
  66. Vicente E, Boer M, Netto C, Fochesatto C, Dalmaz C, Rodrigues SI, Gonçalves CA (2004) Hippocampal antioxidant system in neonates from methylmercury-intoxicated rats. Neurotoxicol Teratol 26:817–823. CrossRefPubMedGoogle Scholar
  67. Yang JM, Jiang XZ, Chen QY, Li PJ, Zhou YF, Wang YL (1996) The distribution of HgCl2 in rat body and its effects on fetus. Biomed Environ Sci 9:437–442PubMedGoogle Scholar
  68. Yin Z, Milatovic D, Aschner JL, Syversen T, Rocha JB, Souza DO, Sidoryk M, Albrecht J, Aschner M (2007) Methylmercury induces oxidative injury, alterations in permeability and glutamine transport in cultured astrocytes. Brain Res 1131:1–10. CrossRefPubMedGoogle Scholar
  69. Zeng H, Schimpf BA, Rohde AD, Pavlova MN, Gragerov A, Bergmann JE (2007) Thyrotropin-releasing hormone receptor 1-deficient mice display increased depression and anxiety-like behavior. Mol Endocrinol 21:2795–2804. CrossRefPubMedGoogle Scholar

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Authors and Affiliations

  1. 1.Biological Engineering Laboratory, Faculty of Sciences and TechniquesSultan Moulay Slimane UniversityBeni MellalMorocco

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