How does mercury cause dendritic-beading (a recently evidenced marker of mercury neurotoxicity)?

Environmental exposure to mercury (Hg) is an underestimated threat. Hg is classified as one of the 3 chemicals of greatest concern for public health, but mercury pollution is constantly increasing. Hg is neurotoxic, particularly to the foetal nervous system. Our aim is to provide new insights into the cellular mechanisms of Hg neurotoxicity. In our latest experiment at ID16A, we imaged the distribution of Hg and arsenic in neurons exposed to low concentrations of these elements. Unlike arsenic, Hg was not detected in synapses but in spherical micro-structures along dendrites, suggesting a different and unknown mechanism of neurotoxicity. Since then, using immunofluorescence experiments we have revealed dendritic beads in neurons exposed to Hg, a marker of neurotoxicity. We now want to determine whether Hg co-locates with dendritic beads. The expected results will contribute to alert about this environmental threat and to suggest prevention strategies.