Associative olfactory learning in the desert locust, Schistocerca gregaria.

Area of Science:

• Neuroscience
• Animal Behavior
• Olfactory Learning

Background:

• Locusts (Schistocerca gregaria) are valuable models for studying olfactory coding and nutritional regulation.
• Previous research on locust olfactory memory relied on operant conditioning, limiting neural mechanism studies.
• Restrained preparations are necessary for electrophysiological recordings of memory acquisition.

Purpose of the Study:

• To develop classical conditioning paradigms for olfactory memory in restrained desert locusts.
• To enable precise experimental control over learning parameters.
• To investigate the neural basis of olfactory memory acquisition.

Main Methods:

• Developed two complementary classical (Pavlovian) appetitive conditioning paradigms for restrained locusts.
• Used maxillary palp opening as a measure of olfactory memory acquisition.
• Assessed memory-influenced decision-making in a Y-maze operant task.

Main Results:

• Locusts showed significantly higher maxillary palp opening to odors paired with food rewards.
• Olfactory memories were acquired after a single conditioning trial and lasted at least 24 hours.
• Trained locusts demonstrated odor-guided choices in a Y-maze, with memory duration dependent on training trials.

Conclusions:

• Classical conditioning effectively establishes appetitive olfactory memories in restrained locusts.
• These memories influence subsequent behavioral decisions, demonstrating their functional relevance.
• The developed paradigms facilitate detailed investigation into the neural mechanisms of olfactory memory.