Scientists suspect that iron accumulation plays a role in neurodegenerative processes such as Parkinson's disease, but its distribution in neurons has never been observed because of the lack of techniques to do so. Until today.
Researchers from CNRS at the University of Bordeaux (France), University of Sevilla (Spain), INSERM Grenoble Institute of Neurosciences (France) and ESRF have studied the iron distribution in an in vitro model of neuronal cells that produce dopamine. Dopamine is a neurotransmitter, a chemical messenger between nerve cells in the mammalian brain. Because dopamine can form stable complexes with iron, Richard Ortega, from the cellular chemical imaging group in Bordeaux, believed that dopamine may exert a protective effect by buffering iron in dopaminergic neurons and that this system might be at fault in Parkinson's disease.
To test this hypothesis, the team used the new nanoprobe imaging experimental station recently developed at the European Synchrotron Radiation Facility to study the distribution of elements in cells. The resolution of 90 nm allowed scientists to visualize the elements distribution in the neurotransmitter vesicles. The nanoprobe consists on exciting the sample with a strongly focused X-ray beam and collecting the characteristic fluorescence signal that is re-emitted. This allows showing the different trace elements in a point, and then the sample is scanned point by point to form a complete multi-element image of the cells.