a b s t r a c t
Background: Aversive olfactory classical conditioning has been the standard method to assess Drosophila
learning and memory behavior for decades, yet training and testing are conducted manually under
exceedingly labor-intensive conditions. To overcome this severe limitation, a fully automated, inexpensive
system has been developed, which allows accurate and efficient Pavlovian associative
learning/memory analyses for high-throughput pharmacological and genetic studies.
New method: The automated system employs a linear actuator coupled to an odorant T-maze with airflowmediated
transfer of animals between training and testing stages. Odorant, airflow and electrical shock
delivery are automatically administered and monitored during training trials. Control software allows
operator-input variables to define parameters of Drosophila learning, short-term memory and long-term
memory assays.
Results: The approach allows accurate learning/memory determinations with operational fail-safes. Automated
learning indices (immediately post-training) and memory indices (after 24 h) are comparable to
traditional manual experiments, while minimizing experimenter involvement.
Comparison with existing methods: The automated system provides vast improvements over laborintensive
manual approaches with no experimenter involvement required during either training or
testing phases. It provides quality control tracking of airflow rates, odorant delivery and electrical shock
treatments, and an expanded platform for high-throughput studies of combinational drug tests and
genetic screens. The design uses inexpensive hardware and software for a total cost of
∼$500US, making
it affordable to a wide range of investigators.
Conclusions: This study demonstrates the design, construction and testing of a fully automated Drosophila
olfactory classical association apparatus to provide low-labor, high-fidelity, quality-monitored, highthroughput
and inexpensive learning and memory behavioral assays.