Mushroom Bodies - Drosophila Melanogaster

Drosophila Melanogaster

We know that mushroom body structures are important for olfactory learning and memory in Drosophila because their ablation destroys this function. The exact roles of the specific neurons making up the mushroom bodies are still unclear. However, these structures are studied extensively because much is known about their genetic make-up. There are three specific classes of neurons that make up the mushroom body: α/β, α’/β’, and γ neurons, which all have distinct gene expression. A main topic of current research is which of these substructures in the mushroom body are involved in each phase and process of learning and memory. Drosophila mushroom bodies are also often used to study learning and memory and manipulated due to their relatively discrete nature. Typically, olfactory learning assays consist of exposing flies to two odors separately; one is paired with electric shock pulses (the conditioned stimulus, or CS+), and the second is not (unconditioned stimulus, or US). After this training period, flies are placed in a T-maze with the two odors placed individually on either end of the horizontal ‘T’ arms. The percent of flies that avoid the CS+ is calculated, with high avoidance considered evidence of learning and memory.