It is likely that NM-bound iron causes paramagnetic T2 shortening effects4. Our results also suggest that NM is one of main sources of a T2*-sensitive contrast in the SN at 7T. The correlation of T2* shortening with the density of NM and the negligible T2* changes in the less-pigmented dopaminergic neurons of the ventral tegmental (A10) and retrorubral (A8) areas support this hypothesis20. However, we are unable to provide histological evidence of the amount of iron bound to NM leading to T2* contrast because ferric iron deposits in NM-containing neurons are not usually detectable by Perls’ staining15.