metal toxicity on brain

Literature review about the metal toxicity in brain, please include just these metal, (nickel, iron, Aluminium, zinc)
provide information about nickel toxicity on new born baby (does it make any modification for the DNA and does it affect boys and girls differently)
How do all metal get inside the brain and pass the blood brain barrier, does it bind to any Low molecular compound (what are they and how to bind them) or just bind to  transferrin in the blood.

please be specific to brain and the side effect of metal on brain provide some studies from the literature that support that and please make sure all references are from high impact paper and new