DOI: 10.25377/sussex.22312216.v1
title: Research data for paper "Geosmin suppresses defensive behaviour and elicits unusual neural responses in honey bees"

description: Research data for paper published in Scientific Reports journal March 2023 This data explores the effects of Geosmin on honeybees and has three separate parts: 1. Behavioural data on the stinging response of bees towards a dummy in the presence of the alarm pheromone and Geosmin 2. Electro-antennogram (EAG) data of the response to Geosmin on bees' antenna 3. Calcium imaging data illustrating the neural response to Geosmin in the honey bee antennal lobe. Data & File Overview File List: <em>Bee_Aggression_Behaviour.csv: </em>Bees' stinging responses towards a rotating dummy <em>Bee_AL_Calcium_imaging.csv:</em> Calcium imaging time traces for individual odour stimuli and glomeruli in all bees <em>Bee_EAG_Data.csv:</em> Electroantennography response amplitudes for individual odour stimuli in all bees Methodological Information all Methods described in: Scarano F, Deivarajan Suresh M, Tiraboschi E, Cabirol A, Nouvian M, Nowotny T, Haase A. Geosmin suppresses defensive behaviour and elicits unusual neural responses in honey bees. Sci Rep 13:3851 (2023) Data-specific Information for: '<em>Bee_Aggression_Behaviour</em>.csv' The data file contains observational data from an aggression assay, where 325 bee dyads were inserted into an arena with a rotating dummy. Data indicates whether a behaviour was observed or not from one or both bees. Further details in the Methods sections of Scarano et al. 2021 Number of variables/columns: 17 Number of cases/rows: 324 Variable List: A) Day: Date in which bees were tested, DD/MM/YYYY B) Weather: Describes the weather on the trial date, Sunny / Cloudy C) Hive: Hive colour recognised by the paint colour from which the bees have been acquired, Orange / White / Green / Yellow D) Dummy: Which of two arenas used in that behavioural trial, A / B E) Group: Represents the odours - VOCs and its mixtures with the respective concentrations, IAA / Geosmin6 / Geosmin3 / IAAGeo3 / IAAGeo6 / Control, Concentrations: 3 (10^-3) & 6 (10^-6) F) Sting.Bee1: Represents if bee one exhibits stinging behaviour, 0 (no) / 1 (yes), binary G) Sting.Bee2: Represents if bee two exhibits stinging behaviour, 0 (no) / 1 (yes), binary H) Recruit.Bee1: Represents if bee one exhibits recruiting behaviour, 0 (no) / 1 (yes), binary I) Recruit.Bee2: Represents if bee two exhibits recruiting behaviour, 0 (no) / 1 (yes), binary J) Grooming/Calm: Represents if the bees exhibit grooming or calm behaviour, 0 (none) /1 /2, number of bees K) Batch: Represents in which time batch the trials were conducted, 1 (Morning) / 2 (Afternoon), numerical – time period L) number.sting: Represents number of bees stinging in a trial, 0/1/2, number of bees M) number.recruit: Represents number of bees recruiting in a trial, 0/1/2, number of bees N) sting.first: Represents if the stinging behaviour was exhibited first in a trial, 0 (no) / 1 (yes), binary O) recruit.first: Represents if the recruiting behaviour was exhibited first in a trial, 0 (no) / 1 (yes), binary P) b.sting: Represents if there was any stinging behaviour exhibited by the two bees during that trial, 0 (no) / 1 (yes), binary Q) b.recruit: Represents if there was any recruiting behaviour exhibited by the two bees during that trial, 0 (no) / 1 (yes), binary Data-specific Information for: '<em>Bee_EAG_Data</em>.csv' Data are electroantennography responses for 24 antennas exposed to different odour stimuli. Data points are voltage change amplitudes with respect to the baseline, averaged over the 1s stimulus duration. Further datails in the Methods sections of Scarano et al. 2021 Number of variables/columns: 16 Number of cases/rows: 24 Variable List: A) Bee: subject numbers B-P) Responses to different Odours and Concentrations Values are average potential change (over 10 repetitions) in response to the presented odour stimuli in units of Volt Odours presented: Control = pure mineral oil (solvent) Geo = geosmin in mineral oil at a concentration indicated in brackets IAA = Isoamil acetate in mineral oil at a concentration indicated in brackets B) Control mineral oil C) Geo (10^-6) D) Geo (10^-5) E) Geo (10^-4) F) Geo (10^-3) G) IAA (10^-3) H) IAA (10^-3)+ Geo (10^-6) I) IAA (10^-3)+ Geo (10^-5) J) IAA (10^-3)+ Geo (10^-4) K) IAA (10^-3)+ Geo (10^-3) L) IAA (10^-1) M) IAA (10^-1)+ Geo (10^-6) N) IAA (10^-1)+ Geo (10^-5) O) IAA (10^-1)+ Geo (10^-4) P) IAA (10^-1)+ Geo (10^-3) Data-specific Information for: '<em>Bee_AL_Calcium_imaging</em>.csv' The data file contains response curve from up to 19 glomeruli in the antennal lobe of 14 bees, data are relative changes in fluorescence averaged over the glomerular area. The fluorescence changes stem from projection neurons that were stained by backfill injection with the calcium-sensitive dye fura-dextrane. Further details in Methods sections of Scarano et al. 2021 Number of variables/columns: 95 Number of cases/rows: 1720 Variable List: A) Bee-id: Subject number B) Glo_id: Glomerulus number following bee antennal lobe standard atlas nomenclature for tract T1 C) Odour: Stimulus odour type Geo6 = Geosmin at concentration 10^-6 in mineral oil Geo3 = Geosmin at concentration 10^-3 in mineral oil IAA = Isoamyl acetate at concentration 10^-1 in mineral oil 3Hex = 3-hexanol at concentration 5x10^-3 in mineral oil acetoph = Acetophenone at concentration 5x10^-3 in mineral oil non = 1-nonanol at concentration 5x10^-3 in mineral oil IAA-Glo are mixtures of both odours D) Response: Automatized response classification (1 activated, 2 background activity, 2 inhibited) E-CQ) Frame_1-91: Glomerular response curves, 91 frames, 10.033 frames/s, Curves cover a 1s prestimulus interval (frames 1-30), 1s stimulus (frames 31-60), and 1s post stimulus (frames 61-91). Values are fluorescence changes in percent, averaged over the glomerular area, background subtracted and normalized with respect to the background. <br> Article Abstract Geosmin is an odorant produced by bacteria in moist soil. It has been found to be extraordinarily relevant to some insects, but the reasons for this are not yet fully understood. Here we report the first tests of the effect of geosmin on honey bees. A stinging assay showed that the defensive behaviour elicited by the bee’s alarm pheromone component isoamyl acetate (IAA) is strongly suppressed by geosmin. Surprisingly, the suppression is, however, only present at very low geosmin concentrations, and disappears at higher concentrations. We investigated the underlying mechanisms at the level of the olfactory receptor neurons by means of electroantennography, finding the responses to mixtures of geosmin and IAA to be lower than to pure IAA, suggesting an interaction of both compounds at the olfactory receptor level. Calcium imaging of the antennal lobe (AL) revealed that neuronal responses to geosmin decreased with increasing concentration, correlating well with the observed behaviour. Computational modelling of odour transduction and coding in the AL suggests that a broader activation of olfactory receptor types by geosmin in combination with lateral inhibition could lead to the observed non-monotonic increasing–decreasing responses to geosmin and thus underlie the specificity of the behavioural response to low geosmin concentrations. Links to other resources relating to the data Computational modelling software that aims at reproducing the Calicum and EAG data indcluded here, is available on https://github.com/tnowotny/bee_al_2021