Mainly responsible: Sadniman Rahman & Michael Schleyer

Finding rewards and avoiding punishments are powerful goals of behavior. To maximize reward and minimize punishment, it is beneficial to learn about the stimuli that predict their occurrence, and decades of research have provided insight into the brain processes underlying such associative reinforcement learning. In addition, it is well known in experimental psychology, yet often unacknowledged in neighboring scientific disciplines, that subjects also learn about the stimuli that predict the absence of reinforcement. In the past years, we studied these learning processes in larval Drosophila. Recently, we found that the same reward-dopamine neuron can induce both kinds of learning. Now, we systematically analyse punishment-dopamine neurons, using a combination of optogenetics, behavioural tracking and connectome analyses.

Mainly responsible: Ayaka Fukushima & Michael Schleyer

Learning and remembering are crucial facilities in life. The mechanisms that regulate how long a memory endures are of great practical importance. Think, for example, of students trying to remember lessons for an exam, or elder people suffering from Alzheimer’s and other form of dementia. 

We study whether and how the presence of substances like sugars or artificial sweeteners can modify memory stability in larvae, and the underlying neuronl circuits (funded by grants by the Akiyama Foundation and the JSPS (Kakenhi)).

Mainly responsible: Michael Schleyer

In order to understand how neuronal circuits modify behaviour, we have to be able to analyse the behaviour in great detail. Together with computer scientists and students, we developed a software for video-tracking and behavioural analyses in Drosophila larvae. We want to further develop and extend this software, and use it to gain new insights in locomotion and goal-directed behaviour. A project using this software for studying the role of dopamine on locomotion is funded by a Kakenhi start-up grant.

Mainly responsible: Naoko Toshima

Amino acids are important nutrients for animals because they are necessary for protein synthesis in particular during growth, as well as for neurotransmission. However, little is known about how animals use past experience to guide their search for amino-acid-rich food. The larvae of Drosophila melanogaster are suitable for investigating this topic because they are the feeding and growth stages in the life cycle. 

Surprisingly, we found that larvae form parallel memories of opposite valence about amino acids that are retrieved dependent on their current situation. Now, we try to decipher the neuronal circuits involved in these parallel memories (funded by a Kakenhi start-up grant).

Mainly responsible: Maia Wang & Michael Schleyer

How do previous experiences, current needs and behavioural options influence decisions? For the larvae, we design simple situations of decisions, for example between an actually present, mediocre food source and a learned stimulus predicting a better food source. Using our software for behavioural analyses and the genetic tools available for Drosophila, we study of the mechanisms underlying such decisions.