Appetitive odor learning does not change olfactory coding in a subpopulation of honeybee antennal lobe neurons

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2006 Oct;192(10):1083-103. doi: 10.1007/s00359-006-0152-3. Epub 2006 Jul 25.


Odors elicit spatio-temporal patterns of activity in the olfactory bulb of vertebrates and the antennal lobe of insects. There have been several reports of changes in these patterns following olfactory learning. These studies pose a conundrum: how can an animal learn to efficiently respond to a particular odor with an adequate response, if its primary representation already changes during this process? In this study, we offer a possible solution for this problem. We measured odor-evoked calcium responses in a subpopulation of uniglomerular AL output neurons in honeybees. We show that their responses to odors are remarkably resistant to plasticity following a variety of appetitive olfactory learning paradigms. There was no significant difference in the changes of odor-evoked activity between single and multiple trial forward or backward conditioning, differential conditioning, or unrewarded successive odor stimulation. In a behavioral learning experiment we show that these neurons are necessary for conditioned odor responses. We conclude that these uniglomerular projection neurons are necessary for reliable odor coding and are not modified by learning in this paradigm. The role that other projection neurons play in olfactory learning remains to be investigated.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Bees / physiology*
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology
  • Calcium / metabolism
  • Cell Count / methods
  • Conditioning, Classical / drug effects
  • Conditioning, Classical / physiology*
  • Discrimination Learning / drug effects
  • Discrimination Learning / physiology*
  • Evoked Potentials / drug effects
  • Evoked Potentials / physiology
  • Fatty Alcohols / pharmacology
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology
  • Neurons / physiology*
  • Odorants*
  • Sense Organs / cytology*
  • Time Factors


  • Fatty Alcohols
  • Calcium