Our research focuses on the anatomy, function and regulation of neuropeptide systems:
- peptidergic coordination of central and peripheral clocks
- circadian control of eclosion (adult emergence)
- role of brain-gut peptides in feeding and foraging
- circadian control of neuroendocrine systems
- neurogenetics of peptide processing
For further information on individual projects, please click on the names of the team members below.
Fruitflies only have around 80.000 neurons (compare this to around 20.000.000.000 neurons in our brain), but nearly as many neuropeptides as humans or other mammals. Neuropeptides are key factors that modulate (fine-tune) small neuronal circuits to perform astonishingly complex tasks and integrations. As hormones, peptides also serve as the chemical information channel between peripheral tissues and the brain. My research focusses on the characterisation of the chemical and cellular structure and function of peptidergic systems in the fruitfly, Drosophila melanogaster. The underlying aim is to understand how the small insect nervous system and the central clock in the brain regulates the activity of peptidergic neurons and the release of peptide hormones within a physiological and behavioural framework. The answers will help us to understand the evolution of peptidergic signaling and its circadian regulation, its significance for the astonishing performance of mini-brains, and the unmatched adaptive flexibility of the most diverse animal group on our planet.
For insects, peptides play a dominant role in the control of foraging, digestion, and metabolism. Peptidergic cells are widespread in the nervous and the digestive system. However, we still know very little about the specific functions of the peptides from enteroendocrine cells. AstA and MIP, two peptide families produced by enteroendocrine cells in the Drosophila midgut. In my PhD project, I concentrate on the functional characterization of these two peptide families and try to find out whether and how they may regulate foraging as well as digestion of Drosophila.
How brains organize behavior based on internal needs on the one hand and changing environmental information on the other is one of the key questions in neuroscience. Learning is defined as a process leading to a lasting alteration in behavior due to experience. Even animals as simple as the Drosophila larva are able to form and recall an association of a particular odor with a rewarding stimulus. In the last years it turned out that - similar to the adult fly – the larval mushroom bodies (MB) are required for diverse behavioral functions, including odor learning and memory. The larval MB consists of about 2000 embryonic and larval born Kenyon cells. The seemingly unlimited genetic toolbox in Drosophila, which allows one to visualize, silence or activate defined neurons, combined with the simplicity in terms of cell numbers, the larva offers a useful system to study the neuronal correlates underlying learning and memory processes. In previous work we could demonstrate that only around 100 embryonic born Kenyon cells are required for associative odor-sugar learning. Furthermore, optogenetic activation of dopaminergic/octopaminergic neurons is sufficient to substitute the unconditional stimulus (US) during conditioning, while optogenetic activation of specific olfactory neurons is sufficient to substitute the conditional stimulus (CS). However, to our knowledge it is still elusive whether the conditional activation of Kenyon cells is sufficient to form memory traces. Thus, I am interested in whether a conditional optogenetic activation of Kenyon cells is, dependent on the set of Kenyon cells included in the Gal4 line, sufficient to induce an appetitive or aversive memory.
Neuropeptides and biogenic amines are key players in the adaptation of neuronal networks to environmental changes. In detail, interactions between neuropeptides or between neuropeptides and biogenic amines like octopamine and dopamine seem to be essential for such adaptations. Similar to vertebrates, invertebrate locomotor activity, nociceptive behavior and learning and memory are affected by these modulators. Our main focus is to identify and understand neuronal circuits modulating the activity, pain behavior and learning and memory in Drosophila.
Which neuropeptide/amine is involved in the modulation of locomotor activity?
Which neuropeptide/amine is involved in the modulation of nociceptive behavior?
Which neuropeptide/amine is involved in the modulation of associative learning and memory?
These studies will help to untangle how various neuropeptides and biogenic amines interact with each other in the adaptation of different behaviors to the metabolic state and available energy resources.sity of Würzburg
Neuropeptides represent the largest group of intercellular signalling molecules in animals and play an important role in the modulation of most neuronal and physiological processes. Interestingly, the release of neuropeptides is often rhythmic, potentially coupled to circadian oscillators in the brain. Insect eclosion is a classical example of a peptide-orchestrated and circadian-timed behavior. The aim of my research is the anatomical and functional dissection of peptidergic and circadian networks involved in eclosion gating in Drosophila melanogaster.