Behavioural strategies and neural mechanisms for robust navigation

• Applicant: Dr. Hannah Haberkern, Ph.D.
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 513850388

Maintaining a stable sense of orientation and choosing appropriate navigational strategies when moving through diverse and dynamic environments is a fundamental and highly complex problem. To achieve robust behaviour and quick adaptation to new situations, our brains generate abstract internal representations of relevant information about our environment, which in turn are used to guide actions. A spatial representation that has been identified in a range of species is a head direction estimate or neural compass. The processing of external sensory stimuli used to update this compass and circuit mechanisms ensuring stability of the compass in dynamic environments are poorly understood. Furthermore, it is largely unknown how such a compass guides behavior and how animals adapt their navigational strategies when their internal compass fails or becomes unstable. The overarching goal of my project is to understand how circuit structure, neurophysiology and behavioral strategies jointly support robust goal-directed navigation. I will take a holistic perspective on neural control of navigation that can be achieved in insect models. To do this, I will complement work in fruit flies, where I can use genetic tools and established calcium imaging recording techniques to monitor and perturb circuits, with behavioral and anatomical studies in an expert navigator, desert ants, where neural adaptation can be better linked to a defined ethological context. Specifically, I will investigate how visual information is organized in the central brain to support a stable neural compass, which will provide insights into how brains process sensory information to extract and represent relevant information enabling efficient computations in downstream circuits. Further, I will study how different, multimodal sensory guidance cues are integrated to support robust orientation, testing predictions about cue reliability and dominance based on my analysis of the fly connectome. A third project will investigate which sensory signals drive different navigational strategies laying the groundwork for understanding neural mechanisms underlying changes in behavioral strategy. Finally, I will study adaptation of circuits through structural plasticity and its implications for orientation using electron microscopy-based circuit reconstruction and modelling. In summary, this research program combines multimodal virtual reality and calcium imaging with behavioral studies and connectomic analysis of circuits to uncover principles by which dynamic, multimodal sensory environments are processed and represented in the brain to support robust navigation.

• DFG Programme: Independent Junior Research Groups
• International Connection: Sweden, USA
• Major Instrumentation: MP Laser ; Multiphoton Microscope w/o MP-Laser
• Instrumentation Group: 5060 Mikroskopbeleuchtung ; 5090 Spezialmikroskope
• Cooperation Partners: Dr. Jan Funke; Professor Dr. Stanley Heinze; Dr. Ann Hermundstad; Professor Dr. Vivek Jayaraman