Chunyu Ann Duan is a systems neuroscientist interested in understanding how complex neural dynamics produce cognitive behaviors on the circuit level. She is currently a postdoctoral fellow in Ninglong Xu’s lab at the Institute of Neuroscience, Chinese Academy of Sciences. After attending Furman University on a full scholarship and graduating summa cum laude in 2010, she went on to perform her Ph.D. work in neuroscience with Dr. Carlos Brody at Princeton University, supported by a HHMI International Student Research Fellowship. During her thesis, Dr. Duan developed a novel, rapid task-switching behavior in the rat to study executive control using recording and inactivation techniques. Contrary to the expected cortical control hypothesis, she found a more distributed network underlying flexible task switching and working memory, including the prefrontal cortex and the midbrain superior colliculus (SC). The surprising result that a reptilian͟ brain region such as the SC plays an essential role in executive control demands an updated model of cortico-subcortical interaction during decision making. It has also inspired Duan’s long-term career goal: to understand how interconnected neural populations work together to generate cognition. For her postdoc, Dr. Duan will combine sophisticated rodent behavior with pathway-specific microscopy and perturbation methods to conduct functional dissection of different cortico-subcortical loops during decision formation and maintenance.
“Imaging cortico-subcortical circuits during perceptual decision making”
Making decisions based on sensory information is a fundamental function of the brain. Much of the time, an animal takes in sensory information, such as sights, smells and sounds, then makes a decision based on that input. However, in some cases, an animal must act on that sensory information at a later time. A present decision that relies on past sensory information requires a simple form of short-term memory. How the brain maintains this memory in the timespan between decision and action is unknown. We propose to study this fundamental form of memory in mice during a task in which the animals must act based on prior sensory information. In our task, the mouse will listen to one of two types of auditory stimuli, and then, depending on the identify of the sound, it has to decide which water spout—left or right—to take a drink from. The twist is that the animals have to wait up to a few seconds between hearing the sound and taking a drink, which presumably requires maintaining a memory of the the motor plan. To understand how this works in the brain, we have developed an experimental setup to observe and manipulate the neural activity in multiple areas of the mouse’s brain. Previous work has suggested that a part of the brain called the “secondary motor cortex,” or M2, is important for memory-guided decisions. But M2 isn’t the whole story. Many other brain regions connected to M2 seem to contribute to the decision, including areas such as the superior colliculus, or SC. In our work, we plan to selectively manipulate the activity of regions such as M2 and SC to reveal how the interaction between these areas forms the basis of the decision, rather than any single brain region alone. More broadly, this work will not only advance our understanding of memory-guided decision-making, it will also make fundamental contributions to how brain regions work together to guide cognitive behaviors.