Synchrotron-based correlative imaging of metals and proteins in neuronal cells: state of the art and future challenges in neurometallomics.

Abstract

Metal homeostasis in the nervous system is subtly regulated and changes in metal distribution or content, either increases or decreases, are associated with neurodegeneration or cognitive impairment. Determining the localization and quantification of metals in different types of neurons is important information for understanding their role in neurobiology. Synchrotron X-ray fluorescence imaging is a powerful technique that provides very high sensitivity and high spatial resolution for imaging metals in cells. However, additional biological information is often required to correlate the subcellular localization of metals with specific proteins or organelles. The purpose of this article is to review the studies in neuroscience that correlate metal imaging by synchrotron X-ray fluorescence with protein localization by other techniques. This article highlights the diversity of correlative modalities that have been used, from fluorescence to super-resolution and infrared microscopy, and the wealth of information that has been extracted, but also discusses some current limitations. Future developments are needed, particularly for direct imaging of metals and proteins with a single instrument.