MYCOLab Ai Logo - gold and army green

Dopamine activity in projection neurons regulates short-lasting olfactory approach memory in Drosophila

Summary

Fruit flies learn to avoid dangerous smells and approach safe smells during training. Scientists discovered that flies form both types of memories at the same time, but they work differently in the brain. Safe-smell memories are made using special brain areas and chemical signals that are different from danger memories. These findings help us understand how brains separate good and bad experiences.

Background

Drosophila melanogaster uses aversive olfactory conditioning to learn associations between sensory cues and danger or safety. While mechanisms of odor-fear associations in mushroom bodies are well-studied, less is known about how flies form approach memories to safety-associated odors during the same conditioning paradigm.

Objective

To demonstrate that single-cycle olfactory aversive conditioning simultaneously forms both avoidance and approach memories, and to identify the distinct neural mechanisms underlying approach memory formation and recall compared to fear memory.

Results

Conditioning forms both shock-paired odor avoidance memory and unpaired odor approach memory. Approach memory is short-lasting (disappears within 3 hours) compared to avoidance memory (persists 24+ hours). D1-like dopamine receptors in both mushroom bodies and projection neurons are required for approach memory, while only mushroom body D1Rs are sufficient for avoidance memory. Mushroom body output is required for avoidance memory recall but not approach memory recall.

Conclusion

Olfactory approach and avoidance memories are formed and recalled using distinct cellular mechanisms in Drosophila, with approach memory depending on dopamine signaling in projection neurons rather than exclusively in mushroom bodies, suggesting separate neural pathways for safety-associated memories.
  • Published in:European Journal of Neuroscience,
  • Study Type:Experimental Research,
  • Source: PMID: 35815601, DOI: 10.1111/ejn.15766
Scroll to Top