Parallel processing of appetitive short- and long-term memories in Drosophila

Curr Biol. 2011 Oct 11;21(19):1647-53. doi: 10.1016/j.cub.2011.08.032. Epub 2011 Sep 29.


It is broadly accepted that long-term memory (LTM) is formed sequentially after learning and short-term memory (STM) formation, but the nature of the relationship between early and late memory traces remains heavily debated [1-5]. To shed light on this issue, we used an olfactory appetitive conditioning in Drosophila, wherein starved flies learned to associate an odor with the presence of sugar [6]. We took advantage of the fact that both STM and LTM are generated after a unique conditioning cycle [7, 8] to demonstrate that appetitive LTM is able to form independently of STM. More specifically, we show that (1) STM retrieval involves output from γ neurons of the mushroom body (MB), i.e., the olfactory memory center [9, 10], whereas LTM retrieval involves output from αβ MB neurons; (2) STM information is not transferred from γ neurons to αβ neurons for LTM formation; and (3) the adenylyl cyclase RUT, which is thought to operate as a coincidence detector between the olfactory stimulus and the sugar stimulus [11-14], is required independently in γ neurons to form appetitive STM and in αβ neurons to form LTM. Taken together, these results demonstrate that appetitive short- and long-term memories are formed and processed in parallel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Conditioning, Operant
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / physiology*
  • Memory, Long-Term
  • Memory, Short-Term
  • Mushroom Bodies / physiology
  • Neurons / physiology
  • Odorants
  • Smell
  • Sucrose / pharmacology


  • Sucrose