Recent instrumentation advances have made it possible to apply experimental synchrotron radiation techniques of materials science to biophysics problems. We present the first results of a systematic photoelectron spectromicroscopy study of the interaction between metals and neurons in vitro. The main result is that aluminum is not uptaken by granule cells-the most common type of neurons-but it is selectively uptaken by cells such as Purkinje neurons and glial cells. On the contrary, granule cells are capable to uptake other metals like Ni and Co.