Impaired odour discrimination on desynchronization of odour-encoding neural assemblies

Mark Stopfer, Seetha Bhagavan, Brian H. Smith, Gilles Laurent

Research output: Contribution to journalArticlepeer-review

747 Scopus citations


Stimulus-evoked oscillatory synchronization of neural assemblies has been described in the olfactory(1-5) and visual(6-8) systems of several vertebrates and invertebrates. In locusts, information about odour identity is contained in the timing of action potentials in an oscillatory population response(9-11), suggesting that oscillations may reflect a common reference for messages encoded in time. Although the stimulus-evoked oscillatory phenomenon is reliable, its roles in sensation, perception, memory formation and pattern recognition remain to be demonstrated a task requiring a behavioural paradigm. Using honeybees, we now demonstrate that odour encoding involves, as it does in locusts, the oscillatory synchronization of assemblies of projection neurons and that this synchronization is also selectively abolished by picrotoxin, an antagonist of the GABA(A) (γ- aminobutyric acid) receptor. By using a behavioural learning paradigm, we show that picrotoxin-induced desynchronization impairs the discrimination of molecularly similar odorants, but not that of dissimilar odorants. It appears, therefore, that oscillatory synchronization of neuronal assemblies is functionally relevant, and essential for fine sensory discrimination. This suggests that oscillatory synchronization and the kind of temporal encoding it affords provide an additional dimension by which the brain could segment spatially overlapping stimulus representations.

Original languageEnglish (US)
Pages (from-to)70-74
Number of pages5
Issue number6655
StatePublished - Nov 6 1997
Externally publishedYes

ASJC Scopus subject areas

  • General


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