Drosophila

Drosophila as an Animal Model for a Depression-like State and Attention Goal 1: Understanding the motivational system of invertebrates. Decisions of flies are based on needs, internal states and external stimuli. In our recent publication Ries et al. (2017) we describe a serotonergic push-pull motivational system residing in the mushroom bodies. It has astounding similarities with the mammalian motivational control system. Goal 2: Understanding the etiology and pathogenesis of depression, stress susceptibility and attention deficits without the ethical problems often associated with vertebrate animal models. In that respect transmitter systems can be influenced both neurogenetically and pharmacologically. Sugar and various antidepressant drugs can make stressed flies “happy” and prevent depression-like states. Overdose, in turn, can cause manic behavior. Foto: Tim Hermanns   Serotoneric system: Ries, A.-S., Hermanns, T., Poeck, B., Strauss, R. (2017) Serotonin modulates a depression-like state in Drosophila responsive to lithium treatment. Nature Communications, 8: article no.: 15738. ...

Goal 1: Understanding the normal function of Amyloid Precursor Protein in nervous systems. In the latest paper by Rieche et al. 2018 we show APP function in a visual working memory of Drosophila. The natural age-related memory impairment can be prevented by changing the processing of APP. Goal 2: Understanding the etiology and pathogenesis of neurodegenerative diseases without the ethical problems often associated with vertebrate animal models. These projects are done in collaboration with medical-oriented groups. Behavior turns out to be often a useful and sensitive early indicator of neurodegenerative processes in the nervous system of flies. The ellipsoid body (green, center) is the seat of the visual working memory of Drosophila. Cells of the R3-ring system are labeled with double-tagged APP to be able to localize its fragments after processing. The N-terminus is tagged with GFP (green) and the C-terminus with RFP (red). Unprocessed APP and processed APP, where ...

Goal: Understanding the underpinnings of a visual working memory and autonomous orientation. We are unravelling the signaling cascades and neuronal network underlying uninterrupted orientation in a cluttered environment. Furthermore, we are analyzing steps of visual information processing enabling distance estimation.   View into the virtual-reality paradigm during a test for the visual working memory. A. The fly approaches a visual object. B. The target disappears and an attractive distracter shows up. The fly reorients. C. The distracter disappears; the fly remembers its initial plan and resumes approaching the original target object.   Visual Working Memory: Kuntz, S., Poeck, B., Strauss, R. (2017). Visual working memory requires permissive and instructive NO/cGMP signaling at presynapses in the Drosophila central brain. Current Biology 27(5): 613-623. Thran, J., Poeck, B., Strauss, R. (2013). Serum Response Factor (SRF) mediated gene regulation in a Drosophila visual working memory. Current Biology 23: 1756-1763. Kuntz, S., Poeck, B., ...

 The Goal: Computer simulations and implementation of robots are a critical test for algorithms and neuronal circuits inferred from biological research. When comparing robot to fly behavior the possible outcomes are (1) the proof of the concept, (2) starting-points for additional research, or (3) disclosure of emergent properties. Technical Spin-off: Biologically inspired construction principles and control algorithms are likely to improve the performance of mobile robots. Feature by Alison Abbott in Nature (Jan. 18, 2007; 445: 250-253) Link                 Left:Six-legged walking robot(PhD-thesis S.Pick;modified Tarryll in collaboration with Prof.Dr. H.Cruse. Bielefeld) Right: Orientation robot with 360°-camera view (PhD-thesis M.Mronz)   Selected publications Arena, E., Arena, P., Strauss, R., Patané, L. (2017) Motor-skill learning in an insect inspired neuro-computational control system. Frontiers in Neurorobotics. https://doi.org/10.3389/fnbot.2017.00012 Arena, P., Calí, M., Patané, L., Portera, A., Strauss R. (2016) A fly-inspired mushroom bodies model for sensory-motor control through sequence ...

The Goal: Understanding of the neuronal circuits and principles underlying the higher control of visual orientation behaviour and terrestrial locomotion. Drosophila lends itself for this analysis as there is a plethora of genetic tools at hand to experimentally modify the neuronal basis. A Screen for Walking Mutants: 230 lines with inheritable defects in walking and orientation behaviour have been isolated in a behavioural screen. 13% of these lines show structural defects in the central complex (Figure), a highly structured neuropil interconnecting the two protocerebral brain hemispheres. The central complex in a frontal section through the fly brain. Role of the Protocerebral Bridge: Five mutant lines with structural protocerebral-bridge defects point to a role of this neuropil in step-length control. We currently analyze two of these genes molecularly. Role of the Fan-Shaped Body: Several lines with fan-shaped body defects indicate a role of this neuropil in right-left bargaining. Role of the ...

The Goal: Understanding of the neuronal circuits and principles underlying the adaptive initiation of motor programmes and the goal-oriented recruitment of groups of muscles within a given motor programme. The Climbing Paradigm: Flies are walking on small blocks with gaps of 1 to 6 mm width. High-speed video cameras monitor the fly from above and from the side. Phases of climbing behaviour The Climbing Process: Different phases can be observed. After stepping into the void with both front legs and a short period of freezing, flies switch from walking to climbing behaviour. The vigour of the attempts is adapted to the width of the gap. At barely surmountable gaps flies fully engage in a combination of behavioural adaptations and reach the biomechanical limit. Contrariwise flies do not attempt to traverse insurmountable gaps. Gap-size is visually estimated. Climbing-Defective Flies: Lines with specific inheritable defects in single aspects of climbing were isolated. ...