Spatially resolved imaging methods to probe metals in the brain: From subcellular to organ level

Abstract

Very little is known about the subcellular distribution of metal ions in cells. Some metals such as zinc, copper, and iron are essential and play an important role in the cell metabolism. Dysfunctions in this delicate housekeeping may be at the origin of major diseases. There is also a prevalent use of metals in a wide range of diagnostic agents and drugs for the diagnosis or treatment of a variety of disorders. This is becoming more and more of a concern in the field of nanomedicine with the increasing development and use of nanoparticles, which are suspected of causing adverse effects on cells and organ tissues and particularly the brain. Various analytical methods are developing into well-suited sub-micrometer analytical tools for addressing new problems when studying the role of metals in the brain. In the present review, we describe the possibilities and some current applications offered by three major techniques that cover imaging of metals from subcellular to organ level, namely synchrotron-based X-ray microspectroscopy, laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) and, less thoroughly addressed, the capabilities of magnetic resonance imaging (MRI) for in vivo imaging of metals in the brain.