TY  - JOUR
A1  - El-Keredy, Amira
A1  - Schleyer, Michael
A1  - König, Christian
A1  - Ekim, Aslihan
A1  - Gerber, Bertram
T1  - Behavioural Analyses of Quinine Processing in Choice, Feeding and Learning of Larval Drosophila
JF  - PLoS One
N2  - Gustatory stimuli can support both immediate reflexive behaviour, such as choice and feeding, and can drive internal reinforcement in associative learning. For larval Drosophila, we here provide a first systematic behavioural analysis of these functions with respect to quinine as a study case of a substance which humans report as "tasting bitter". We describe the dose-effect functions for these different kinds of behaviour and find that a half-maximal effect of quinine to suppress feeding needs substantially higher quinine concentrations (2.0 mM) than is the case for internal reinforcement (0.6 mM). Interestingly, in previous studies (Niewalda et al. 2008, Schipanski et al 2008) we had found the reverse for sodium chloride and fructose/sucrose, such that dose-effect functions for those tastants were shifted towards lower concentrations for feeding as compared to reinforcement, arguing that the differences in dose-effect function between these behaviours do not reflect artefacts of the types of assay used. The current results regarding quinine thus provide a starting point to investigate how the gustatory system is organized on the cellular and/or molecular level to result in different behavioural tuning curves towards a bitter tastant.
KW  - honeybees
KW  - chemosensory system
KW  - bitter taste
KW  - melanogaster
KW  - receptor
KW  - reward
KW  - brain
KW  - organization
KW  - architecture
KW  - perception
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130811
VL  - 7
IS  - 7
ER  - 
TY  - JOUR
A1  - Appel, Mirjam
A1  - Scholz, Claus-Jürgen
A1  - Müller, Tobias
A1  - Dittrich, Marcus
A1  - König, Christian
A1  - Bockstaller, Marie
A1  - Oguz, Tuba
A1  - Khalili, Afshin
A1  - Antwi-Adjei, Emmanuel
A1  - Schauer, Tamas
A1  - Margulies, Carla
A1  - Tanimoto, Hiromu
A1  - Yarali, Ayse
T1  - Genome-Wide Association Analyses Point to Candidate Genes for Electric Shock Avoidance in Drosophila melanogaster
JF  - PLoS ONE
N2  - Electric shock is a common stimulus for nociception-research and the most widely used reinforcement in aversive associative learning experiments. Yet, nothing is known about the mechanisms it recruits at the periphery. To help fill this gap, we undertook a genome-wide association analysis using 38 inbred Drosophila melanogaster strains, which avoided shock to varying extents. We identified 514 genes whose expression levels and/or sequences covaried with shock avoidance scores. We independently scrutinized 14 of these genes using mutants, validating the effect of 7 of them on shock avoidance. This emphasizes the value of our candidate gene list as a guide for follow-up research. In addition, by integrating our association results with external protein-protein interaction data we obtained a shock avoidance- associated network of 38 genes. Both this network and the original candidate list contained a substantial number of genes that affect mechanosensory bristles, which are hairlike organs distributed across the fly's body. These results may point to a potential role for mechanosensory bristles in shock sensation. Thus, we not only provide a first list of candidate genes for shock avoidance, but also point to an interesting new hypothesis on nociceptive mechanisms.
KW  - functional analysis
KW  - disruption project
KW  - natural variation
KW  - complex traits
KW  - networks
KW  - behavior
KW  - flies
KW  - temperature
KW  - genetics
KW  - painful
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-152006
VL  - 10
IS  - 5
ER  - 
TY  - JOUR
A1  - Appel, Mirjam
A1  - Scholz, Claus-Jürgen
A1  - Kocabey, Samet
A1  - Savage, Sinead
A1  - König, Christian
A1  - Yarali, Ayse
T1  - Independent natural genetic variation of punishment- versus relief-memory
JF  - Biology Letters
N2  - A painful event establishes two opponent memories: cues that are associated with pain onset are remembered negatively, whereas cues that coincide with the relief at pain offset acquire positive valence. Such punishment-versus relief-memories are conserved across species, including humans, and the balance between them is critical for adaptive behaviour with respect to pain and trauma. In the fruit fly, Drosophila melanogaster as a study case, we found that both punishment-and relief-memories display natural variation across wild-derived inbred strains, but they do not covary, suggesting a considerable level of dissociation in their genetic effectors. This provokes the question whether there may be heritable inter-individual differences in the balance between these opponent memories in man, with potential psycho-clinical implications.
KW  - associative memory
KW  - Drosophila melanogaster
KW  - natural genetic variation
KW  - opponent processes
KW  - punishment
KW  - fruit-flies
KW  - relief
KW  - reward
KW  - rats
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186554
VL  - 12
IS  - 12
ER  -