The aggregation of proteins in certain parts of the brain (amyloid plaques) and the action of reactive oxygen species (oxidative stress) on brain cells are two of the mechanisms that are thought to be involved in epilepsy. In the context of a study of the origins of this disease, three European teams joined forces to investigate these ideas using infrared microspectroscopy by synchrotron radiation on the SMIS beamline. Mappings of the distribution of biochemical compounds (proteins, lipids, nucleic acids) were performed on sections of brains from rats in which epileptic seizures had been induced by chemical means. The method chosen, combined with the brilliance of the synchrotron radiation, revealed differences between healthy and unhealthy tissue and provided sub-cellular spatial resolution. The differences observed were twofold: firstly, concerning the distribution and degree of saturation of lipids, the proportion of polyunsaturated lipids is lower in unhealthy tissue. Secondly, a modification of the secondary structure of the proteins was detected. β-sheet structures appear in the cells of the unhealthy animals. These results tend to confirm the involvement of oxidative stress as well as the role of metallic ions in the onset of epilepsy.
Reference:
Chwiej, J., Dulinska, J., Janeczko, K., Dumas, P., Eichert, D., Dudala, J., & Setkowicz, Z.
Synchrotron FTIR micro-spectroscopy study of the rat hippocampal formation after pilocarpine-evoked seizures.
Journal of Chemical Neuroanatomy, 2010, Article in Press.
