EN
Drugs of abuse may cause acute as well as chronic damage to the nervous system, and a common mechanism of neurotoxicity is to induce disturbances in mitochondrial function. The mitochondrion is also an important source for cytotoxic reactive oxygen species (ROS). If the mitochondrial membrane potential (MMP) becomes depolarized, it can increase the production of ROS. This project has evaluated whether the fluorophore JC-1, which measures the depolarization of MMP, and the fluorophore H2DCFDA that oxidizes and produce fluorescence in the presence of oxygen radicals, are useful tools to screen for drug-induced neurotoxicity. The studies have been performed in embryonal carcinoma (EC) P19 cells that are pluripotent and upon retinoic acid (RA)-treatment will differentiate in culture into neurons, astrocytes and oligodendrocytes. In order to determine the predictive validity of the model/methods, a number of compounds known to cause oxidative stress and mitochondrial dysfunction have been examined (hydrogen peroxide, ionomycin, sodium azide). Main techniques employed culturing, induction and differentiation of neuronal cells, pharmacological dose-response experiments, detection and quantification of fluorescence using microplate reader and fluorescence microscopy, microplate-based colorimetric methods for assessment of cell viability, pharmacological/toxicological data and statistical analyses using the GraphPad prism software.