Honeybee Dance Communication
Honeybee dance communication conveys information about the reward value as well as the direction and distance of a profitable food source. In the last years my former colleagues and I started research projects to identify neural circuits and neuromodulators involved in dance behaviour. At NCBS we continue this line of research focusing on two aspects: (a) individual variation in dance activity and neuromodulatory systems involved in dance behaviour, and (b) time dynamics of processing and encoding distance information in the waggle run.
(a) Individual variability and plasticity of dance behaviour
Previous experiments on dance behaviour demonstrated huge individual variations in dance activity. These experiments also indicated that most of the dances within a foraging group, i.e. all foragers visiting the same food source, are done by a few individuals (Seeley, 1994). We started studying inter-individual variation in dance activity with a focus on two questions: (1) Is the individual dance activity consistent over time? (2) Does the composition of the foraging group affect individual dance activity?
Similar to the earlier experiments, we found strong differences in dance activity among individuals of a foraging group (6 -12 foragers). Furthermore, the relative dance activity of individual foragers remained constant over the 3-5 experimental days. We then started manipulation experiments in which we remove foragers, which show the highest dance activity, from the foraging group. First results suggest that changes in the composition of the foraging group affect individual dance activity. Parallel to these behavioural experiments we collaborate with C-CAMP to develop mass-spectrometry procedures to measure neurotransmitter and neuromodulator titres in single honeybee brains to test whether the differences in dance behaviour correlate with differences in neuromodulator systems.
Students involved : Ebi Antony George
(b) Time dynamics of processing and encoding distance information in the waggle run.
Generally, dance experiments are done using a group of bees and the duration and direction information of waggle runs are determined as a population mean. We started to do experiments in which we record all waggle runs of individually identified foragers and analyse the variation in duration and direction of waggle runs for each individual. Furthermore, we use this approach to monitor how individual foragers change their dance behaviour in response to changes in feeder distances. Our major question is whether honeybees instantaneously change the waggle run duration or whether they need time to process and encode the new information in waggle run duration.
Students involved : Arumoy Chatterjee, Prabhudev M V
Collaborators: Gene E. Robinson (University of Illinois, USA), Kannan R (C-CAMP), Taketoshi Kiya (Kanazawa University, Japan)
Honeybee dance communication conveys information about the reward value as well as the direction and distance of a profitable food source. In the last years my former colleagues and I started research projects to identify neural circuits and neuromodulators involved in dance behaviour. At NCBS we continue this line of research focusing on two aspects: (a) individual variation in dance activity and neuromodulatory systems involved in dance behaviour, and (b) time dynamics of processing and encoding distance information in the waggle run.
(a) Individual variability and plasticity of dance behaviour
Previous experiments on dance behaviour demonstrated huge individual variations in dance activity. These experiments also indicated that most of the dances within a foraging group, i.e. all foragers visiting the same food source, are done by a few individuals (Seeley, 1994). We started studying inter-individual variation in dance activity with a focus on two questions: (1) Is the individual dance activity consistent over time? (2) Does the composition of the foraging group affect individual dance activity?
Similar to the earlier experiments, we found strong differences in dance activity among individuals of a foraging group (6 -12 foragers). Furthermore, the relative dance activity of individual foragers remained constant over the 3-5 experimental days. We then started manipulation experiments in which we remove foragers, which show the highest dance activity, from the foraging group. First results suggest that changes in the composition of the foraging group affect individual dance activity. Parallel to these behavioural experiments we collaborate with C-CAMP to develop mass-spectrometry procedures to measure neurotransmitter and neuromodulator titres in single honeybee brains to test whether the differences in dance behaviour correlate with differences in neuromodulator systems.
Students involved : Ebi Antony George
(b) Time dynamics of processing and encoding distance information in the waggle run.
Generally, dance experiments are done using a group of bees and the duration and direction information of waggle runs are determined as a population mean. We started to do experiments in which we record all waggle runs of individually identified foragers and analyse the variation in duration and direction of waggle runs for each individual. Furthermore, we use this approach to monitor how individual foragers change their dance behaviour in response to changes in feeder distances. Our major question is whether honeybees instantaneously change the waggle run duration or whether they need time to process and encode the new information in waggle run duration.
Students involved : Arumoy Chatterjee, Prabhudev M V
Collaborators: Gene E. Robinson (University of Illinois, USA), Kannan R (C-CAMP), Taketoshi Kiya (Kanazawa University, Japan)
Social Foraging and Decision-making
Individual foragers visit a food source over several days flying back and forth between the nest and the food source. We suggest that this foraging activity can be divided into at least six distinct sub-behaviours: (1.) Leaving the hive, (2) flying towards the food source, (3.) collecting food, (4) flying back home, (5) delivering the food and recruiting nest mates, and (6.) resting. With respect to current ideas on behavioural decision-making we propose that the sub-behaviours of honeybee foraging are accompanied and regulated via the activity of different neuromodulator systems.
Our research pursues three goals: (a) Comprehensive analysis of changes in neuromodulators associated with the different sub-behaviours during foraging (b) developing strategies to monitor neuromodulator changes in brain regions and neuron populations, and (c) identification of the behavioural function of the candidate neuromodulators using manipulative lab assays.
Students involved : Divya R, Aridni Shah
Collaborators: Padma R. (C-CAMP), Susanne Neupert and Reinhard Predel (University of Köln, Germany)
Individual foragers visit a food source over several days flying back and forth between the nest and the food source. We suggest that this foraging activity can be divided into at least six distinct sub-behaviours: (1.) Leaving the hive, (2) flying towards the food source, (3.) collecting food, (4) flying back home, (5) delivering the food and recruiting nest mates, and (6.) resting. With respect to current ideas on behavioural decision-making we propose that the sub-behaviours of honeybee foraging are accompanied and regulated via the activity of different neuromodulator systems.
Our research pursues three goals: (a) Comprehensive analysis of changes in neuromodulators associated with the different sub-behaviours during foraging (b) developing strategies to monitor neuromodulator changes in brain regions and neuron populations, and (c) identification of the behavioural function of the candidate neuromodulators using manipulative lab assays.
Students involved : Divya R, Aridni Shah
Collaborators: Padma R. (C-CAMP), Susanne Neupert and Reinhard Predel (University of Köln, Germany)
Sex-pheromone Communication and identifying new Genes involved in Olfactory Transduction and Sensitivity
One of the most successful strategies in neuroethology is to use “natural experiments” to understand fundamental biological questions. We plan to use the sex-pheromone sensitive olfactory system of drone (male) honeybees to identify new genes and proteins involved in olfactory transduction and sensitivity. This project is based on two hypotheses. First, the male sex-pheromone sensitive olfactory system is under strong selection to detect and rapidly respond to minute amounts of sex-pheromone. There are two basic strategies to increase olfactory sensitivity, one is to enlarge the olfactory epithelium and the other is to improve the underlying molecular transduction machinery. Second, the mating behaviour of honeybees is regulated by the circadian clock and we expect that genes and proteins involved in sex-pheromone detection are also likely to be regulated by the circadian clock. If so, then in reverse antennal genes and proteins, which are expressed or synthesized in synchrony with mating time are highly likely involved in olfactory processing. Currently we perform preliminary experiments demonstrating circadian changes in olfactory sensitivity and antennal gene expression.
Students involved : Rikesh Jain, Yogesh Pandey
Collaborators: R. Swodhamini (NCBS), Wolfgang Roessler and Johannes Spaethe (University of Würzburg, Germany)
One of the most successful strategies in neuroethology is to use “natural experiments” to understand fundamental biological questions. We plan to use the sex-pheromone sensitive olfactory system of drone (male) honeybees to identify new genes and proteins involved in olfactory transduction and sensitivity. This project is based on two hypotheses. First, the male sex-pheromone sensitive olfactory system is under strong selection to detect and rapidly respond to minute amounts of sex-pheromone. There are two basic strategies to increase olfactory sensitivity, one is to enlarge the olfactory epithelium and the other is to improve the underlying molecular transduction machinery. Second, the mating behaviour of honeybees is regulated by the circadian clock and we expect that genes and proteins involved in sex-pheromone detection are also likely to be regulated by the circadian clock. If so, then in reverse antennal genes and proteins, which are expressed or synthesized in synchrony with mating time are highly likely involved in olfactory processing. Currently we perform preliminary experiments demonstrating circadian changes in olfactory sensitivity and antennal gene expression.
Students involved : Rikesh Jain, Yogesh Pandey
Collaborators: R. Swodhamini (NCBS), Wolfgang Roessler and Johannes Spaethe (University of Würzburg, Germany)
Asian Honeybees and the Evolution of Behaviour
Traditionally behavioural and neurobiological research in honeybees focused on the European-African species A. mellifera neglecting the variability in social organization and individual behaviour among honeybee species. Worldwide there are nine species of honeybees and three of them: A. florea, A. dorsata and A. cerana, which represent major phylogenetic lineages, are native to India. We have started comparative research projects on the visual and olfactory systems and behaviours, and colony organization and division of labour. In the long run we are interested in studying neural and molecular changes underlying evolutionary changes in behaviour.
(a) The bee curtain in open-nesting species and the evolution of division of labour among honeybee species
Colonies of open-nesting honeybee species (e.g. A. florea and A. dorsata) build only one comb and the workers form a cluster of multiple layers, the bee curtain, which covers the whole comb. The bee curtain functions as a protective shield against unfavourable environmental conditions and predators. First studies on the bee curtain suggested that open-nesting species have a specific “curtain bee” worker caste not present in the cavity-nesting species like A. mellifera. Unfortunately, so far such a worker caste has never been identified with respect to behaviour and physiology. We started a detailed analysis of the functional organization of the bee curtain and division of labour in A. florea. We investigated three different aspects of the curtain: (1) Massed flight activity and the opening of the curtain, (2) string-organization of the curtain, and (3.) movement patterns of individual bees on the outer layer of the curtain. Our observations of massed flight activity showed that strings or chains of worker bees clinging to each other form the curtain. These string bees might be recognized as a specific worker caste and represent what other authors have described as curtain bees. Our next experiments will focus on the behavioural and molecular analysis of adult behavioural maturation and the caste status of string bees.
Students involved : Hemalatha B
Traditionally behavioural and neurobiological research in honeybees focused on the European-African species A. mellifera neglecting the variability in social organization and individual behaviour among honeybee species. Worldwide there are nine species of honeybees and three of them: A. florea, A. dorsata and A. cerana, which represent major phylogenetic lineages, are native to India. We have started comparative research projects on the visual and olfactory systems and behaviours, and colony organization and division of labour. In the long run we are interested in studying neural and molecular changes underlying evolutionary changes in behaviour.
(a) The bee curtain in open-nesting species and the evolution of division of labour among honeybee species
Colonies of open-nesting honeybee species (e.g. A. florea and A. dorsata) build only one comb and the workers form a cluster of multiple layers, the bee curtain, which covers the whole comb. The bee curtain functions as a protective shield against unfavourable environmental conditions and predators. First studies on the bee curtain suggested that open-nesting species have a specific “curtain bee” worker caste not present in the cavity-nesting species like A. mellifera. Unfortunately, so far such a worker caste has never been identified with respect to behaviour and physiology. We started a detailed analysis of the functional organization of the bee curtain and division of labour in A. florea. We investigated three different aspects of the curtain: (1) Massed flight activity and the opening of the curtain, (2) string-organization of the curtain, and (3.) movement patterns of individual bees on the outer layer of the curtain. Our observations of massed flight activity showed that strings or chains of worker bees clinging to each other form the curtain. These string bees might be recognized as a specific worker caste and represent what other authors have described as curtain bees. Our next experiments will focus on the behavioural and molecular analysis of adult behavioural maturation and the caste status of string bees.
Students involved : Hemalatha B
Studying Honeybee Behaviour with Drosophila
We establish procedures to use the fruit fly Drosophila melanogaster to identify neural circuits involved in honeybee behaviour, and in particular honeybee dance behaviour. Conceptually, we dissect dance behaviour, or any other complex behaviour, into several different simpler behaviours or behavioural modules, which can be found in Drosophila. For these simpler behaviours we then develop lab assays that can be performed with both, fruit flies and honeybees. This research strategy follows ideas by the American entomologist Vincent Dethier who suggested, more than fifty years ago, that the relatively simple sugar-elicited search behaviour found in flies might be a solitary behaviour that had been integrated into the more complex social dance behaviour. Sugar-elicited search and dance behaviour have in common that the initiation and intensity of both behaviours is dependent on the hunger state of the animal and the reward value (i.e. sugar concentration) of the food. We established lab assays for sugar-elicited search behaviour for honeybees and Drosophila and are currently investigating the modulatory systems involved in regulating this behaviour. We expect that the same modulatory systems are likely involved in the regulation of honeybee dance behaviour.
Students involved : Manal Shakeel, Ravi Kumar B
Collaborators: Teiichi Tanimura (Kyushu University, Japan)
We establish procedures to use the fruit fly Drosophila melanogaster to identify neural circuits involved in honeybee behaviour, and in particular honeybee dance behaviour. Conceptually, we dissect dance behaviour, or any other complex behaviour, into several different simpler behaviours or behavioural modules, which can be found in Drosophila. For these simpler behaviours we then develop lab assays that can be performed with both, fruit flies and honeybees. This research strategy follows ideas by the American entomologist Vincent Dethier who suggested, more than fifty years ago, that the relatively simple sugar-elicited search behaviour found in flies might be a solitary behaviour that had been integrated into the more complex social dance behaviour. Sugar-elicited search and dance behaviour have in common that the initiation and intensity of both behaviours is dependent on the hunger state of the animal and the reward value (i.e. sugar concentration) of the food. We established lab assays for sugar-elicited search behaviour for honeybees and Drosophila and are currently investigating the modulatory systems involved in regulating this behaviour. We expect that the same modulatory systems are likely involved in the regulation of honeybee dance behaviour.
Students involved : Manal Shakeel, Ravi Kumar B
Collaborators: Teiichi Tanimura (Kyushu University, Japan)