Long-term social memory of mate copying in Drosophila melanogaster is localized in mushroom bodies.

Long-term social memory (LTSM) is a key feature to elicit the cultural inheritance of behaviour independently of genetics. However, the neurobiological basis of LTSM remains largely unknown. We previously used the Drosophila animal model, which is known to perform mate copying through observational learning of the mate choice of conspecifics to show that the expression of the rutabaga gene, a calcium/calmodulin-dependent adenylyl cyclase (AC-Rut+) that acts as a coincidence detector enabling associative learning, is necessary and sufficient in the γ-Kenyon cells (KCs) of the mushroom bodies (MBs). Here, we show that the expression of AC-Rut in both the γ- and the α/β-KCs is required for LTSM involving de novo protein synthesis in a mate-copying context, whether using demonstrations involving real flies or involving pictures of copulating conspecifics. Thus, pathways of short- and long-term memory show considerable overlap in the MBs across social vs. asocial learning contexts.