Sensory control of 3D navigation: The making and breaking of spatial habits

• Applicant: Dr. Daria Genzel-Wehrfritz
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; Sensory and Behavioural Biology
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 287265713

Spatial navigation and its neural basis have risen to a major topic in systems neuroscience, reflected in the Nobel Prize award of 2015 in physiology and medicine. While navigating through known environments animals gradually form spatial habits, a cost efficient behavior. A key area in the brain underlying such habit formation is the dorsal striatum, which contains anatomically and functionally segregated neural circuits believed to play complementary roles in spatial habit formation. The dorsomedial part of the striatum (DMS) is thought to process multimodal and cognitive information and is associated with more exploratory and goal-directed behaviors. The dorsolateral striatum (DLS) is hypothesized to be involved in sensory-motor associations and is suggested to be in charge of cue learning and habit formation. The mechanism underlying the transition from exploratory to habitual behavior is still unknown. As the only flying mammals, bats move in three-dimensional (3D) space and allow for a direct behavioral read-out of their 3D space assessment through their directional biosonar emissions. In this project we propose a novel experimental approach to address open questions concerning spatial learning, habit formation and behavioral flexibility while navigating in 3D space. Specifically, we will first quantify the perceptual saliency of landmarks in different sensory modalities and subsequently use these landmarks to break habitual navigation by our bats through a maze. We hypothesize that a transition from habitual to sensory-driven navigation will coincide with a significant change of the neural code in DMS and DLS. Building upon the expertise in my host lab, we will design experiments where, through recording neural activity from the DMS and DLS of freely flying bats, neural activity can be directly correlated with the detailed behavioral read-out that is provided by the bat. Comparing these electrophysiological recordings will disclose the underlying neural computation of spatial behavior during the different navigational tasks. Finally we will investigate the effect of pharmacological and optogenetic silencing of either the DMS or DLS on the navigational capabilities of bats. We hypothesize that the combinatorial results emerging from these neural and behavioral investigations will let us predict the behavioral outcome depending on which striatal area is functionally inactive. Combining my expertise in sensory control of freely behaving bats with the electrophysiological skills of my host lab, established neurophysiological methods and his knowledge about the cortical circuits underlying 3D navigation maximizes the chances of success in this experimental challenge. We are confident that these experiments will allow teasing apart the transitional stages from exploratory, sensory driven navigation via the buildup of spatial memory to habitual behavior and quantify the flexibility of these transitions at both the behavioral and neuronal level.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Dr. Michael Yartsev