Classical Conditioning of Adult<i>Drosophila</i>

Olfactory classical conditioning paradigms have been extensively used since the early 1970s to apply genetic approaches to the study of memory in <i>Drosophila.</i> Over the intervening years, advances in genetics have largely changed the focus of studies from the role of single genes in memory to investigation of memory-relevant neuronal circuits. However, the original behavioral paradigms have remained largely unaltered, besides investigators making a few useful tweaks to the training and testing apparatus and modifications to the operating procedures. In this protocol, we provide the reader with a detailed description of the manufacture and assembly of a typical T-maze apparatus, where populations of adult flies can be trained and their odor memory tested later, by giving them a binary choice between the two trained odors. We describe how variations of the training apparatus permit both aversive (odor-shock) and appetitive (odor-sugar) memories to be studied. In addition, we describe a recent modification of the apparatus and protocol that permits study of multisensory (color and odor) aversive and appetitive learning. Control assays for sensory acuity and locomotion are also included.