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Interference of ethanol and methylmercury in the developing central nervous system

Authors :
Maia, Cristiane do Socorro Ferraz
de Souza Lucena, Greice Maria Rodrigues
Corrêa, Pollyanna Barbosa Farias
Serra, Raphael Borges
de Melo Matos, Robson Willian
Menezes, Flávia da Cunha
dos Santos, Setsuko Noro
de Sousa, João Batista
Costa, Edmar Tavares da
Ferreira, Vania Maria Moraes
Source :
NeuroToxicology. Jan2009, Vol. 30 Issue 1, p23-30. 8p.
Publication Year :
2009

Abstract

Abstract: Studies involving alcohol and its interactions with other neurotoxicants represent the focus of several works of research due to the fact that the use of alcohol can sometimes leads to serious health problems. Fetal exposure to alcohol and mercury has a high incidence in some regions of Brazil, where there are pregnant women who are alcoholics and live in mining areas. This work was conducted to examine the effects of combined exposure to ethanol (EtOH) and methylmercury (MeHg) in rats during the development of the central nervous system (CNS). Experimental behavioral animal models/tests were used in order to examine locomotion, anxiety, depression and memory. Pregnant rats received tap water or EtOH 22.5% w/v (6.5g/kg per day), by gavage) during pregnancy and breast-feeding. On the 15th day of pregnancy, some groups received 8mg/kg of MeHg (by gavage). The groups were as follows: control, EtOH, MeHg and EtOH+MeHg. The experimental results showed that the EtOH, MeHg and EtOH+MeHg groups reduced the percentage of frequency and time spent in the open arms entries of the elevated plus-maze (EPM) test, when compared to the control group. This result suggests an anxiogenic behavioral response. The MeHg group increased locomotor activity in the arena and the immobility time in the forced swimming test, suggestive of depression-like behavior. The EtOH+MeHg group showed greater reductions in the percentages of frequency and time spent in the open arms entries in the EPM test, suggesting a sedative-behavior since the frequency of enclosed arm entries was affected. In the inhibitory avoidance task, the EtOH+MeHg group reduced the latency of the step-down response onto the grid floor, suggesting a cognitive and behavior dysfunctions. Taken together, the results suggest that EtOH and/or MeHg intoxication during the developing CNS may be a risk for deficits related to locomotor impairment, anxiety, depression and neurocognitive functions. There is a possibility that EtOH may prevent some of the MeHg responses, but the precise mechanism of action involved in this process needs to be considered for future research. [Copyright &y& Elsevier]

Details

Language :
English
ISSN :
0161813X
Volume :
30
Issue :
1
Database :
Academic Search Index
Journal :
NeuroToxicology
Publication Type :
Academic Journal
Accession number :
36189857
Full Text :
https://doi.org/10.1016/j.neuro.2008.11.008