Our understanding of the health effects of Mn exposure to humans is also evolving, and recent research indicates that elevated Mn concentrations in drinking water may lead to developmental disorders in children, among other adverse health effects [6 9].
Indeed, a similar situation is observed in cell culture, where optimal recombination activity is almost reached after a 15 mn exposure to Cre conjugates (see Additional file 2E).
Several in vitro and in vivo rodent studies have linked increased Mn exposure to alterations in concentrations and metabolism of neurotransmitters, in particular, dopamine, GABA, and Glu (Burton and Guilarte 2009).
Past studies of children have linked Mn exposure to hyperactive (Bouchard et al. 2007) and classroom behavior (Khan et al. 2011), deficits in memory, poorer intellectual functioning (Bouchard et al. 2011; Menezes-Filho et al. 2011; Wasserman et al. 2006), and poorer learning (Collipp et al. 1983; Pihl and Parkes 1977).
In smf-1 and smf-3 but not in smf-2 mutants, increased Mn exposure led to decreased Fe levels, suggesting that both metals compete for transport by SMF-2.
In human manganism, chronic Mn exposure leads to symptoms resembling PD, such as poorly coordinated and slowed movements, and tremors (Crossgrove and Zheng, 2004; Roth, 2009).
At the cellular level, Mn exposure leads to mitochondrial dysfunction, release of reactive oxygen species, altered neurotransmitter metabolism and release and eventual cell death (Martinez-Finley et al., 2013).
The occurrence of changes in ERK activity and JNK activity after Mn exposure, added to the absence of cell viability loss, suggests that the modulation of MAPK signaling pathway represents a primary event induced by Mn.
The bli-3 e767 bli-3 e767rain exhibited hyperresistance to mutantostrainnd failexhibitedw any increase in ROS levels upon increasing levels of Mn exposure, and thyperresistanceosure to Mn and exposures Dandid not afailedtoe showitivity of the worms to Mn, any results that have not been shown to occur increasetype worms.
For example, we showed that low Mn exposures (0.1 mM) tend to increase and high concentrations (100 mM) to decrease smf gene expression (Fig. 9).
