Honey bees form separate memory traces after experiences containing appetitive and aversive consequences

KLAPPEBACH MARTIN; FERNANDO LOCATELLI

San Diego, CA

Congreso; Meeting of the Society for Neuroscience 2018; 2018

Society for Neuroscience

In natural situations animals must be able acquire information fromexperiences that combine appetitive and aversive consequences. How learningderived from those experiences is stored and retrieved to produce adaptivebehaviour is a major question in the field of the neurobiology of learning andmemory. Honey bees have been lengthily used to study olfactory learning andmemory processes triggered upon olfactory conditioning of the proboscisextension response. In its appetitive version, animals associate odour withsugar reward and learn to extend the proboscis in response to the odour. In theaversive version, the odour is associated with a salty or a bitter solution,and the behaviour observed is the withdrawal of the proboscis in response tothe learned odour. In the present study we performed a series of experimentsaimed at evaluating in which extend, these two forms of learning interact whenappetitive and aversive stimuli are intrinsic parts of the same trainingprotocol. First of all, we established a new protocol focused on measuring the occurrenceand duration of aversive memory. In an initial part of this protocol the beesreceive paired presentations of an odour and quinine bitter solution. Nolearning becomes evident during training immediately evoident We used areversal learning protocol in which bees have to switch the valence of thelearnt odor from aversive to appetitive. Bees trained in the aversive paradigmshowed a deficit in the appetitive learning. At contrast with appetitivememory, we found that multiple trials of aversive conditioning endow a memorythat lasts only 24 hours. Then, combining the two differenttraining protocols we showed that animals are able to form two separatememories during a simultaneous training session and that these memories withopposite valence are both expressed the following days. As a next step, we demonstrated that honeybees can recognize theaversive learnt odour in a binary mixture of odours. Finally, we performed anexperiment in which after differential conditioning, in which one odor wasassociated with the appetitive stimulus while the other was associated with theaversive stimulus bees were tested with an odour mixture that contained theappetitive and the aversive conditioned odours. During test, bees behavedalternatively according to the appetitive or to the aversive odour depending ontheir satiation level. In summary, using a different way form to reveal the aversive memoryretention combined with the classical PER conditioning we showed that animalsare able to associate to different odors with opposite stimuli, and that, whenan odor mixture contain conflictive information animals behave accordingly totheir motivational state.