As a result of nuclear power plants accidents such as Chernobyl or Fukushima, some people were exposed to external and internal ionising radiation (IR). Human brain is highly sensitive to IR during foetal and postnatal period when the molecular processes are not completely finished. Various studies have shown that exposure to low doses of IR causes a higher incidence of cognitive impairment. On the other hand, in industrialised countries, people are daily exposed to a number of toxicant pollutants. Exposure to environmental chemicals, such as paraquat (PQ), may potentiate the toxic effects induced by radiation on brain development. In this study, the authors evaluated the cognitive effects of concomitant exposure to low doses of internal radiation ((137)Cs) and PQ during neonatal brain development. At the postnatal day 10 (PND10), two groups of mice (C57BL/6J) were exposed to (137)Cs (4000 and 8000Bq/kg) and/or PQ (7mg/kg). To investigate the spontaneous behaviour, learning, memory capacities and anxiety, behavioural tests were conducted in the offspring at two months of age. The results showed that cognitive functions were not significantly affected when (137)Cs or PQ were administered alone. However, alterations in the working memory and anxiety were detected in mice exposed to (137)Cs combined with PQ.
Authors: Heredia L, Bellés M, Llovet MI, Domingo JL, Linares V. ;Full Source: Toxicology. 2015 Mar 2;329:73-9. doi: 10.1016/j.tox.2015.01.012. Epub 2015 Jan 17. ;