The fruitfly Drosophila melanogaster : a promising model to explore molecular psychiatry

Sawa and colleagues describe a novel model of sleep disturbance by generating transgenic flies in which DISC1 is expressed in the mushroom body, a brain region important for sleep regulation. As shown in the figures, selective expression of a transgene in the mushroom body is induced by the GAL4-based GeneSwitch system by the addition of RU486 in Drosophila brain. Male flies that express wild-type DISC1 in the mushroom body showed reduced arousal state as evidenced by increased sleep time per day without exhibiting disturbance in circadian activity pattern. Fruitflies have been used as excellent invertebrate models to explore basic molecular functions in brains as well as models for neurodegenerative disorders, such as Parkinson's and Huntington's diseases. This work with DISC1 transgenics implies that the fruitflies are also useful to explore molecular pathology of psychiatric conditions. For more information on this topic, please refer to the article by Sawamura et al. on pages 1138–1148.