Sehdev A, Szyszka P

Odor-background segregation of unknown odorants based on stimulus onset asynchrony in honey bees

bioRxiv, 2019

• Honey bees can use stimulus onset asynchrony to segregate unknown odorants from background (unknown odorant = odorant that has not been smelled before, and that has no innate or learned valence)
• The effective stimulus onset asynchrony is two orders of magnitude larger than the previously reported stimulus asynchrony sufficient for segregating known odorants
• We discuss the implications for neural mechanisms underlying odor-background of known versus unknown odorants

Sehdev A, Mohammed YG, Triphan T, Szyszka P

Olfactory object recognition based on fine-scale stimulus timing in Drosophila

iScience, 2019

• Flies can detect whether two mixed odorants arrive synchronously or asynchronously
• This temporal sensitivity occurs for odorants with innate and learned valences
• Flies’ behavior suggests use of odor onset asynchrony for odor source segregation

Chan HK, Hersperger F, Marachlian E, Smith BH, Locatelli F, Szyszka P, Nowotny T 

Odorant mixtures elicit less variable and faster responses than pure odorants

PLoS Comp Biol, 2018

• Extended standard olfactory receptor model predicts that odorant-evoked activity patterns are more stable across concentrations and first-spike latencies of receptor neurons are shorter for mixtures than for pure odorants.
• The more stable activity patterns result from the competition between different ligands for receptor sites.
• Shorter first-spike latencies arise from the nonlinear dependence of binding rate on odorant concentration, commonly described by the Hill coefficient.
• Neuronal responses in Drosophila and honey bees confirm model predictions.