Social foraging extends associative odor-food memory expression in fruit flies (Drosophila melanogaster)

Sehdev A, Mohammed Y, Tafrali C, Szyszka P

bioRxiv, 2019

• Automated foraging assay for groups of walking flies for studying the effect of group size on odor-food learning
• Inter-fly attraction increases with group size
• Flies in groups exhibit extended odor-food memory expression, as compared to single or pairs of flies

Alpha oscillations govern interhemispheric spike timing coordination in the honey bee brain

Popov T, Szyszka P

bioRxiv, 2019

• Alpha wave-like brain activity in the honey bee
• Stimulus-induced alpha suppression
• Cross-frequency coupling of high gamma activity to the phase of the ongoing alpha oscillation

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

Sehdev A, Szyszka P

bioRxiv, 2019

• Honey bees can use stimulus onset asynchrony to segregate unknown odorants from mixtures (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 propose different neural mechanisms for segregating known versus unknown odorants.

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

Sehdev A, Mohammed YG, Triphan T, Szyszka P

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

Odorant mixtures elicit less variable and faster responses than pure odorants

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

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.