Combinatorial and chemotopic odorant coding in the zebrafish olfactory bulb visualized by optical imaging

Neuron. 1997 May;18(5):737-52. doi: 10.1016/s0896-6273(00)80314-1.


Odors are thought to be represented by a distributed code across the glomerular modules in the olfactory bulb (OB). Here, we optically imaged presynaptic activity in glomerular modules of the zebrafish OB induced by a class of natural odorants (amino acids [AAs]) after labeling of primary afferents with a calcium-sensitive dye. AAs induce complex combinatorial patterns of active glomerular modules that are unique for different stimuli and concentrations. Quantitative analysis shows that defined molecular features of stimuli are correlated with activity in spatially confined groups of glomerular modules. These results provide direct evidence that identity and concentration of odorants are encoded by glomerular activity patterns and reveal a coarse chemotopic organization of the array of glomerular modules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / pharmacology
  • Animals
  • Calcium / metabolism
  • Denervation
  • Dose-Response Relationship, Drug
  • Image Processing, Computer-Assisted
  • Multivariate Analysis
  • Nerve Regeneration / physiology
  • Olfactory Bulb / cytology
  • Olfactory Bulb / physiology*
  • Olfactory Nerve / cytology
  • Olfactory Nerve / physiology
  • Olfactory Receptor Neurons / chemistry
  • Olfactory Receptor Neurons / physiology
  • Presynaptic Terminals / chemistry
  • Presynaptic Terminals / physiology
  • Receptors, Odorant / drug effects
  • Receptors, Odorant / physiology*
  • Smell / physiology*
  • Zebrafish / physiology*


  • Amino Acids
  • Receptors, Odorant
  • Calcium