New neural histological methods based on molecular genetic techniques have been used to reveal the delicate structure of Drosophila's neural system. Due to the research on the formation and retrieval of memory, mushroom bodies might play an important role in the formation of long-term memory, and the signal transmission between the dorsal paired medial cells and the mushroom bodies might contribute a lot to the retrieval process of memory. Experiments in different paradigms on the flight-simulator have demonstrated the existence of some advanced functions of the mushroom bodies, so as to provide more evidences to the research on the integration of visual signals.