The olfactory conditioning assay is widely used in Alzheimer’s disease research to quantify learning and memory in Drosophila melanogaster. The assay tests ability to recall an aversive conditioned stimulus of scent paired with electrical shock when presented a choice between shock-associated and unrelated scents. The T-maze, a commonly used apparatus for olfactory conditioning assays, employs an elevator mechanism to transfer live flies from the shock-delivering training chamber to the scent selection point. This elevator mechanism is known to cause fly casualty. T-mazes are not commercially available and often difficult to reproduce. Other existing variations of olfactory conditioning apparatuses use airflow or automated machinery to transfer flies in place of the elevator. These alternative methods are known to inflict stress on flies during transfer, potentially altering conditioning effectiveness. A new, single-chamber apparatus was designed to address these concerns. The design consolidates the training chamber and scent selection point into one space, eliminating the need for transfer. The chamber features a flexible copper printed circuit board, which is powered off to convert the space to the non-shocking selection point. A multi-opening slider component provides controlled access to the chamber, streamlining fly insertion, training, testing, and removal. All structural elements are 3D printed, allowing for simple reproduction and alteration if desired. In preliminary trials, the single-chamber design displayed both minimal fly casualty and promise in functioning as a suitable alternative for traditional olfactory conditioning apparatuses.
Bronovitskiy, Sasha; Castillo, Andres; Yan, Michael; and Lin, Fang Ju
"Consolidated Chamber Design and Protocol for Olfactory Conditioning Assay with Drosophila Melanogaster,"
Journal of the South Carolina Academy of Science: Vol. 21:
1, Article 8.
Available at: https://scholarcommons.sc.edu/jscas/vol21/iss1/8