Research Group Olfactory Coding

Animals use sensory systems to navigate the environment in a way that optimizes their survival and reproduction. The olfactory system plays here a major role in encoding chemical information and translating the outside world into a neuronal representation that enables an animal to take odor-guided decisions.

The main goal of our research is to decipher the neuronal mechanisms underlying olfactory coding and processing in the context of odor-guided behavior in insects with the emphasis on Drosophila melanogaster. The vinegar fly represents a premier model system for studying olfactory processing mechanisms since it exhibits a stereotyped architecture which is similar to its mammalian counterpart, but is less complex and highly tractable as well as susceptible to genetic manipulations. By combining the genetic advantages of Drosophila with neurophysiological, molecular and behavioral methods, we are dissecting the neural circuits that are involved in coding, processing and perception of odors.

Methods:

We exploit neurogenetic methods in Drosophila to visualize, monitor and functionally manipulate selective olfactory circuits. We use functional imaging (widefield and 2-photon microscopy) to monitor neuronal activity across specific populations of olfactory neurons. To compare our functional imaging data between individuals and neuronal processing levels, we map the odor-evoked responses in the antennal lobe to identified glomeruli using our in vivo Drosophila AL Atlas. We employ photoactivation via photoactivatable GFP at the 2-photon microscope to label and visualize single neurons. Subsequent neuronal reconstructions are done with the segmentation software AMIRA and reconstructed neurons are registered in our standard in vivo brain for a comparative approach. In order to determine innate olfactory behavior we use a variety of different behavioral assays that have been established in our Department over last years, such as the FlyWalk, wind tunnel or T-maze. We collaborate with bioinformaticians for imaging data analysis and computational modeling.

Current research projects in our group are:

  • Interaction of excitatory and inhibitory olfactory pathways
  • Processing and integration of odor blends with opposing valences
  • Identification of higher-order neurons that readout odor significance
  • Plasticity and modulation of olfactory circuits
  • Odor coding and behavior in kissing bugs
Dr. Silke Sachse

Group Leader:

Dr. Silke Sachse
+49 (0)3641 57 1405
e-mail