This is a non-randomized, open-label, five treatment, fixed sequence cross-over study to investigate the effect of RO5186582 treatment on CYP3A activity using midazolam as a probe CYP3A substrate, and also to assess the pharmacodynamic measures of brain electrical activity and sedation to explore the pharmacodynamic interaction between the gama-amino butyric acid (GABA)A negative allosteric modulator RO5186582 and the prototypical GABAA positive allosteric modulator midazolam. The anticipated study duration is up to nine weeks.