Mushroom Body Ablation Impairs Short-Term Memory and Long-Term Memory of Courtship Conditioning in Drosophila melanogaster

We have evaluated the role of the Drosophila mushroom bodies (MBs) in courtship conditioning, in which experience with mated females causes males to reduce their courtship toward virgins (Siegel and Hall, 1979). Whereas previous studies indicated that MB ablation abolished learning in an olfactory conditioning paradigm (deBelle and Heisenberg, 1994), MB-ablated males were able to learn in the courtship paradigm. They resumed courting at naive levels within 30 min after training, however, while the courtship of control males remained depressed 1 hr after training. We also describe a novel courtship conditioning paradigm that established long-term memory, lasting 9 days. In MB-ablated males, memory dissipated completely within 1 day. Our results indicate that the MBs are not required for learning and immediate recall of courtship conditioning but are required for consolidation of short-term and long-term associative memories.