Drosophila alpha/beta mushroom body neurons form a branch-specific, long-term cellular memory trace after spaced olfactory conditioning

Neuron. 2006 Dec 7;52(5):845-55. doi: 10.1016/j.neuron.2006.10.030.


Functional optical imaging showed that odor or electric shock stimuli presented to the fly causes transient calcium influx into the two major axon branches of alpha/beta mushroom body (MB) neurons. One pairing of odor and electric shock stimuli or multiple, massed pairings did not alter odor-evoked calcium influx. In contrast, animals that received multiple, spaced pairings exhibited a robust increase in calcium influx into the MB axons when tested at 9 or 24 hr after training, but not at 3 hr. This modification occurred only in the alpha branch of the neurons and was blocked by mutation of the amnesiac gene, inhibition of protein synthesis, or the expression of a protein blocker of the transcription factor Creb. Thus, behavioral long-term olfactory memory appears to be encoded as a branch-specific modification of calcium influx into the alpha/beta MB neurons that occurs after spaced training in a protein synthesis-, Creb-, and amnesiac-dependent way.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Behavior, Animal / physiology
  • Calcium / metabolism
  • Calcium / physiology
  • Conditioning, Operant / physiology*
  • Cyclic AMP Response Element-Binding Protein / genetics
  • Cyclic AMP Response Element-Binding Protein / physiology
  • Cycloheximide / pharmacology
  • Drosophila / physiology*
  • Electroshock
  • Hot Temperature
  • Image Processing, Computer-Assisted
  • Memory / physiology*
  • Microscopy, Confocal
  • Mushroom Bodies / physiology*
  • Neuronal Plasticity / physiology
  • Neurons / physiology*
  • Protein Synthesis Inhibitors / pharmacology
  • Smell / physiology*


  • Cyclic AMP Response Element-Binding Protein
  • Protein Synthesis Inhibitors
  • Cycloheximide
  • Calcium