Abstract
The Drosophila mushroom body (MB) contains about 2500 Kenyon cell (KC) neurons in each hemisphere, divided into five groups: the γ, α’/β’, pioneer α/β, early α/β, and late α/β MB neurons. Studies have shown, hydroxyurea, fed to newly hatched larvae, had selectively abolished the MB structure. Adult flies without MB behaved normally in most situations, but were unable to learn under the classical conditioning because the neurotransmitter output from MB is essential for memory formation. The Drosophila memory formation phases can further be dissected into acquisition, consolidation and retrieval phase. Previous studies have suggested that the retrieval of both the middle term memory (MTM) and long term memory (LTM) require the output from MB neurons. In our previous studies, we have known that blocking total MB synaptic outputs abolish memory formation. Our studies further dissect the role of different MB lobes in the memory formation processes. Unlike previous studies about memory retrieval in MB which only define the role of one of specific MB lobes, our studies figure out the roles of all different MB subsets. Blocking α’/β’ subset of MB neurons specifically disrupt MTM acquisition and retrieval, whereas blocking α/β neurons only affecting retrieval of MTM. Our results imply the main function of MB α’/β’ lobes are memory acquisition, whereas both α’/β’ and α/β lobes are essential for memory retrieval. However, different subset of MB neurons may play different role during the memory formation process.