Julie Semmelhack
Hong Kong University of Science and Technology
Speaker Information
Julie SemmelhackHong Kong University of Science and Technology |
GCNI Symposium "Windows on the Brain" Speaker Information |
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Julie Semmelhack graduated from Princeton University with a degree in Molecular Biology, and did her PhD at UC San Diego, working on the Drosophila olfactory system in Jing Wang's lab. She began working on the zebrafish visual system as a postdoc with Herwig Baier, first at UC San Francisco and then Max Planck Institute for Neurobiology in Martinsried, Germany. Julie started her lab at HKUST in 2017, and is using functional imaging and quantitative analysis of behavior to understand the neural circuits for visual behaviors.
The visual system can process diverse stimuli and make the decision to execute appropriate behaviors, but it remains unclear where and how this transformation takes place. We imaged the zebrafish visual system while larvae responded with hunting, freezing, and escape behaviors, and systematically identified visually driven neurons and behaviorally correlated sensorimotor neurons. We found that broadly tuned sensory neurons are functionally connected to sensorimotor neurons that respond specifically during one behavior, and this transformation occurs in the optic tectum. We also identified sensorimotor neurons in four other areas downstream of the tectum, and these neurons are also specific for one behavior, indicating that once the decision to behave has been made in the tectum, the segregation of the pathways continues in later areas. Our findings suggest that the tectum receives visual sensory information and is responsible for selecting a single behavioral outcome, which is then relayed to downstream areas.
https://scholar.google.com/citations?user=KSJmVb4AAAAJ&hl=en