Methylphenidate effects on cell growth and maturation in neuronal stem cells

Objectives: Based on experiments in rats it was discussed that the treatment of attentiondeficit hyperactivity disorder with the (psycho)stimulant methylphenidate (MPH) may affect the maturation of the dopaminergic system. Neural stem cells (NSC) play a key role in the development of the central nervous system. The aim of this study was to investigate the effect of MPH on the differentiation of NSC. Methods: NSC were derived from hippocampus tissue of mouse embryos on embryonic day 15. Cells were cultured by a modification of previously described methods and collected and plated after 6 days. Cells were treated with different concentrations of MPH (0nM, 1nM, 10nM or 100nM) for 4 days. At the last day cells were fixed with 4% paraformaldehyde and stained with rabbit monoclonal antibody against glia fibrillary acid protein (1:200), with mouse monoclonal antibody against beta-tubulin III (1:300) and Hoechst 33258(1:100). The double staining were analysed for cell count of astrocytes and immature neurons in comparison to the total number of cells. Results: Using 1nM MPH the maturation of NSC into neurons and the appearance of astrocytes were increased, in contrast the highest concentration of MPH decreased these parameters. Conclusion: Our preliminary results suggest an effect of MPH on maturation and differentiation of hippocampal NSC.