Revisiting olfactory classical conditioning of the proboscis extension response in honey bees: A step toward standardized procedures

Real-world experiences do often mix appetitive and aversive events. Understanding the ability of animals to extract, store and use this information is an important issue in neurobiology. We used honey bees as model to study learning and memory after a differential conditioning that combines appetitive and aversive training trials. First of all, we describe an aversive conditioning paradigm that constitutes a clear opposite of the well known appetitive olfactory conditioning of the proboscis extension response. A neutral odour is presented paired with the bitter substance quinine. Aversive memory is evidenced later as an odour-specific impairment in appetitive conditioning. Then we tested the effect of mixing appetitive and aversive conditioning trials distributed along the same training session. Differential conditioning protocols like this were used before to study the ability to discriminate odours, however they were not focused on whether appetitive and aversive memories are formed. We found that after a differential conditioning, honey bees establish independent appetitive and aversive memories that do not interfere with each other during acquisition or storage. Finally, we moved the question forward to retrieval and memory expression to evaluate what happens when appetitive and the aversive learned odours are mixed during test. Interestingly, opposite memories compete in a way that they do not cancel each other out. Honey bees showed the ability to switch from expressing appetitive to aversive memory depending on their satiation level.

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Pollen reinforces learning in honey bee pollen foragers but not in nectar foragers

Journal of Experimental Biology ◽

10.1242/jeb.230250 ◽

2020 ◽

Vol 223 (22) ◽

pp. jeb230250

Author(s):

Denise Nery ◽

Emilia Moreno ◽

Andrés Arenas

Keyword(s):

Honey Bees ◽

Physiological Mechanism ◽

Simultaneous Presentation ◽

Division Of Labour ◽

Proboscis Extension Response ◽

Reinforced Learning ◽

Proboscis Extension ◽

Foraging Specialization ◽

Better Than

ABSTRACTSearching for reward motivates and drives behaviour. In honey bees Apis mellifera, specialized pollen foragers are attracted to and learn odours with pollen. However, the role of pollen as a reward remains poorly understood. Unlike nectar, pollen is not ingested during collection. We hypothesized that pollen (but not nectar) foragers could learn pollen by sole antennal or tarsal stimulation. Then, we tested how pairing of pollen (either hand- or bee-collected) and a neutral odour during a pre-conditioning affects performance of both pollen and nectar foragers during the classical conditioning of the proboscis extension response. Secondly, we tested whether nectar and pollen foragers perceive the simultaneous presentation of pollen (on the tarsi) and sugar (on the antennae) as a better reinforcement than sucrose alone. Finally, we searched for differences in learning of the pollen and nectar foragers when they were prevented from ingesting the reward during the conditioning. Differences in pollen-reinforced learning correlate with division of labour between pollen and nectar foragers. Results show that pollen foragers performed better than nectar foragers during the conditioning phase after being pre-conditioned with pollen. Pollen foragers also performed better than nectar foragers in both the acquisition and extinction phases of the conditioning, when reinforced with the dual reward. Consistently, pollen foragers showed improved abilities to learn cues reinforced without sugar ingestion. We discussed that differences in how pollen and nectar foragers respond to a cue associated with pollen greatly contribute to the physiological mechanism that underlies foraging specialization in the honeybee.

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Do Honey Bees (Apis mellifera) Form Cognitive Representations of Unconditioned Stimuli?

International Journal of Comparative Psychology ◽

10.46867/ijcp.2020.33.00.02 ◽

2020 ◽

Vol 33 ◽

Author(s):

Kiri Li N. Stauch ◽

Harrington Wells ◽

Charles I. Abramson

Keyword(s):

Apis Mellifera ◽

Honey Bees ◽

Experimental Designs ◽

Not Given ◽

Cognitive Representation ◽

Proboscis Extension Response ◽

Cognitive Representations ◽

Avoidance Behaviors ◽

The Us ◽

Proboscis Extension

Previous research looking at expectancy in animals has used various experimental designs focusing on appetitive and avoidance behaviors. In this study, honey bees (Apis mellifera) were tested ina series of three proboscis extension response (PER) experiments to determine to what degree honey bees’ form a cognitive-representation of an unconditioned stimulus (US). Tthe first experiment, bees were presented with either a 2 sec. sucrose US or 2 sec. honey US appetitive reward and the proboscis-extension duration was measured under each scenario. The PER duration was longer for the honey US even though each US was presented for just 2 sec. Honey bees in the second experiment were tested during extinction trials on a conditioned stimulus (CS) of cinnamon or lavender that was paired with either the sucrose US or honey US in the acquisition trials. The proportion of bees showing the PER response to the CS was recorded for each extinction trial for each US scenario, as was the duration of the proboscis extension for each bee. Neither measure differed between the honey US and sucrose US scenarios, In experiment three, bees were presented with a cinnamon or lavender CS paired with either honey US or sucrose US in a set of acquisition trials, but here the US was not given until after the proboscis was retracted. The PER duration after the CS, and again subsequent after the US, were recorded. While the PER duration after the US was longer for honey, the PER duration after the CS did not differ between honey US and sucrose US.

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Honey Bees Can Taste Amino and Fatty Acids in Pollen, but Not Sterols

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.684175 ◽

2021 ◽

Vol 9 ◽

Author(s):

Fabian A. Ruedenauer ◽

Niklas W. Biewer ◽

Carmen A. Nebauer ◽

Maximilian Scheiner ◽

Johannes Spaethe ◽

...

Keyword(s):

Fatty Acids ◽

Honey Bees ◽

Chemical Compounds ◽

Nutritional Composition ◽

Successful Development ◽

Proboscis Extension Response ◽

Foraging Decisions ◽

Proboscis Extension ◽

Plant Pollen

The nutritional composition of food is often complex as resources contain a plethora of different chemical compounds, some of them more, some less meaningful to consumers. Plant pollen, a major food source for bees, is of particular importance as it comprises nearly all macro- and micronutrients required by bees for successful development and reproduction. However, perceiving and evaluating all nutrients may be tedious and impair quick foraging decisions. It is therefore likely that nutrient perception is restricted to specific nutrients or nutrient groups. To better understand the role of taste in pollen quality assessment by bees we investigated nutrient perception in the Western honey bee, Apis mellifera. We tested if the bees were able to perceive concentration differences in amino acids, fatty acids, and sterols, three highly important nutrient groups in pollen, via antennal reception. By means of proboscis extension response (PER) experiments with chemotactile stimulation, we could show that honey bees can distinguish between pollen differing in amino and fatty acid concentration, but not in sterol concentration. Bees were also not able to perceive sterols when presented alone. Our finding suggests that assessment of pollen protein and lipid content is prioritized over sterol content.

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An Automated Apparatus for Conditioning Proboscis Extension in Honey Bees, Apis mellifera L.

Journal of Entomological Science ◽

10.18474/0749-8004-36.1.78 ◽

2001 ◽

Vol 36 (1) ◽

pp. 78-92 ◽

Cited By ~ 18

Author(s):

Charles I. Abramson ◽

B. J. Boyd

Keyword(s):

Apis Mellifera ◽

Classical Conditioning ◽

Unconditioned Stimulus ◽

Pavlovian Conditioning ◽

Discrimination Learning ◽

Honey Bees ◽

Automatic Programming ◽

Wide Range ◽

Proboscis Extension ◽

Series Of Experiments

An apparatus is described for the study of classical conditioning of proboscis extension in harnessed honey bees, Apis mellifera L., that permits automatic programming of events and recording of data. The apparatus is easy to use, accommodates a wide range of stimuli and can be used to study both associative and nonassociative learning. The technique was evaluated in a series of experiments in which the performance of bees was compared under automated and traditional methods of conditioning. The results indicated that the automated apparatus can successfully be used to study Pavlovian conditioning, discrimination learning, and habituation. A unique finding was that the odor of honeycomb can serve as an unconditioned stimulus to support Pavlovian conditioning.

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Behavioural Pharmacology in Classical Conditioning of the Proboscis Extension Response in Honeybees (Apis mellifera)

Journal of Visualized Experiments ◽

10.3791/2282 ◽

2011 ◽

Cited By ~ 13

Author(s):

Johannes Felsenberg ◽

Katrin B. Gehring ◽

Victoria Antemann ◽

Dorothea Eisenhardt

Keyword(s):

Apis Mellifera ◽

Classical Conditioning ◽

Proboscis Extension Response ◽

Proboscis Extension

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Exposure to a biopesticide interferes with sucrose responsiveness and learning in honey bees

Scientific Reports ◽

10.1038/s41598-020-76852-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Daniele Carlesso ◽

Stefania Smargiassi ◽

Lara Sassoli ◽

Federico Cappa ◽

Rita Cervo ◽

...

Keyword(s):

Side Effects ◽

Honey Bees ◽

Long Term Memory ◽

Proboscis Extension Response ◽

Main Determinant ◽

Proboscis Extension ◽

Chemical Pesticides ◽

Careful Assessment ◽

Sucrose Responsiveness

AbstractThe entomopathogenic fungus Beauveriabassiana is a widely used biopesticide that is considered as an effective alternative to classical agrochemicals. B. bassiana is thought to be safe for pollinators although little is known about its side-effects on pollinators’ behaviour and cognition. Here, we focused on honey bees and used the proboscis extension response (PER) protocol to assess whether B. bassiana affects individual sucrose responsiveness, non-associative and associative olfactory learning and memory. Fungus-treated bees displayed an enhanced sucrose responsiveness, which could not be explained by metabolic alterations. Strikingly, exposed bees were twice as inconsistent as controls in response to sucrose, showing PER to lower but not to higher sucrose concentrations. Exposed bees habituated less to sucrose and had a better acquisition performance in the conditioning phase than controls. Further, neither mid- nor long-term memory were affected by the fungus. As sucrose responsiveness is the main determinant of division of foraging labour, these changes might unsettle the numerical ratio between the sub-castes of foragers leading to suboptimal foraging. Although the use of biocontrol strategies should be preferred over chemical pesticides, careful assessment of their side-effects is crucial before claiming that they are safe for pollinators.

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