Zinc uptake by brain cells: 'Surface' versus 'bulk'

The uptake of zinc by cerebellar rat cultures upon exposure to ZnCl2 solutions was comparatively investigated using two well known condensed matter physics techniques: synchrotron photoelectron spectromicroscopy and inductively coupled plasma atomic emission spectroscopy. The objective was to apply a strategy-well known in surface physics-to distinguish between 'surface' and 'bulk' phenomena. The results clearly demonstrate that exposure significantly enhances the bulk (cell cytoplasm) Zn concentration with respect to the physiological level, whereas the effect on the surface (cell membrane) is negligible.