Haberkern lab - Behavioural strategies and neural mechanisms for robust navigation

How do animals know where they are and choose appropriate navigational strategies?
Navigating through diverse and dynamic environments is a fundamental and complex problem. To achieve robust navigation, our brains need to generalize knowledge across ever changing environmental conditions. This can be achieved by generating abstract representations that extract relevant information from the environment. One such abstract representation that is found from insects to humans, is a head direction estimate or neural compass. We investigate how the brain processes the sensory environment to update this compass, and we aim to identify the circuit mechanisms that ensure the compass stability in dynamic environments. We also study how the compass function and the current environment jointly govern the choice between different navigational strategies. Finally, we investigate how these circuits are adapted to different environmental conditions through structural plasticity and to different lifestyles through evolution.

We study multiple insect species that each bring unique experimental advantages
In fruit flies (Drosophila melanogaster) we can use genetic tools and established calcium imaging techniques to monitor and perturb defined populations of neurons. In desert ants (Cataglyphis), which show exquisite and robust navigation behaviour, we can study navigation in the laboratory and the field, and in a defined ethological context. Finally, we also study the same circuits in a blind ant, the clonal raider ant (Ooceraea biroi), which lives underground and, in contrast to our other modes, does not use vision. We compare these models across multiple axes: anatomical circuit structure, behaviour and physiology.      

Connecting circuits to behaviour
Our goal is to understand how neural activity drives behaviour. To get there, we combine a range of cutting-edge techniques:

• immersive virtual reality (VR) to simulate natural environments in the laboratory
• in-vivo 2-photon calcium imaging in actively behaving flies (in VR)
• high-resolution volume electron microscopy for connectomics

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• Linking the functional organisation of sensory information in the central brain to robustness of compass estimates in dynamic, multimodal environments
   
• Uncovering rules for multimodal integration and cue preference for a robust compass estimate. For example, the role of visual landmarks during foraging walks under conflicting celestial cues.
   
• Characterization of sensory signals driving choice of different navigational strategies. For example, how wavelength and light intensity influence orientation behavior in Drosophila and the role of local vs. distant visual cues on dispersal.
   
• Food preferences of Cataglyphis nodus under different nutritional requirements.
   
• Establishing a food-reward paradigm for inducing homing behavior in virtual reality
   
• Reconstructing the head-direction circuit of eyeless, subterranean O.biroi to reveal how an internal compass is anchored without vision.