Journal of Comparative Physiology A

, Volume 192, Issue 10, pp 1083–1103

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

Original Paper

DOI: 10.1007/s00359-006-0152-3

Cite this article as:
Peele, P., Ditzen, M., Menzel, R. et al. J Comp Physiol A (2006) 192: 1083. doi:10.1007/s00359-006-0152-3

Abstract

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.

Keywords

Learning and memory Olfactory coding Calcium imaging Projection neurons Coding invariance 

Abbreviations

AL

Antennal lobe

CR

Conditioned response

CS−

Non-rewarded stimulus

CS+

Rewarded (conditioned) stimulus

ITI

Inter-trial interval

l-ACT

Lateral antenno-cerebralis tract

LP

Lateral protocerebrum

m-ACT

Medial antenno-cerebralis tract

MB

Mushroom body

ml-ACT

Mediolateral antenno-cerebralis tract

OB

Olfactory bulb

OSN

Olfactory sensory neuron

PN

Projection neuron

RM ANOVA

Repeated measures analysis of variance

SEG

Subesophageal ganglion

T1–T4

Tracts 1–4 in the antennal lobe

US

Unconditioned stimulus

PER

Proboscis extension reflex

VUMmx1

Ventral unpaired neuron # 1 of the maxillary neuromere

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • P. Peele
    • 1
  • M. Ditzen
    • 1
  • R. Menzel
    • 1
  • C. G. Galizia
    • 1
    • 2
    • 3
  1. 1.Institute of NeurobiologyFreie Universität BerlinBerlinGermany
  2. 2.Department of EntomologyUniversity of CaliforniaRiversideUSA
  3. 3.Universität KonstanzKonstanzGermany

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