Trehan, Romita

As a PhD student in the Haberkern Lab, I am interested in studying the neural basis of visually guided navigation. To find food, shelter, mates, or avoid predators, finding efficient strategies to navigate large distances is essential for the animal’s survival. A basic navigational strategy is menotaxis, where the animal maintains an arbitrary heading relative to an external cue, like the sun. Another way is to perform phototaxis, that is movement towards or away from the light source. In addition, animals can also perform object tracking or beaconing towards a visual landmark. All these strategies allow animals to travel in a straight line and disperse across landscapes.

At any given time, many visual features are present in the environment, and an animal needs to choose an appropriate strategy based on its internal state and the available external visual cues. This raises a key question: what visual features favor one strategy over another, and how does the animal decide which strategy to use? This is the focus of my PhD.

I work with Drosophila melanogaster, which is an excellent model organism due to its genetic accessibility, easy rearing and now a full wiring diagram of the brain and the ventral nerve cord. My goal is to map the visual conditions that favor different navigational behaviors in Drosophila using a closed loop 2D virtual reality setup, EthoVR. This allows me to present custom designed virtual worlds and stimuli. Combined with genetic perturbations of select neural populations and in-vivo calcium imaging, I aim to link these behaviors to neural circuits within the fly's brain.

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