Dr. Chunyu Ann Duan
Principal Investigator Sainsbury Wellcome Centre, London
Postdoctoral Fellow Institute of Neuroscience, Chinese Academy of Sciences, Shanghai
PhD in Neuroscience Princeton University
Written by Caitlin Ashcroft
From an early age, Dr. Chunyu Ann Duan’s father taught her about eminent female scientists like Marie Curie and inspired her (or brainwashed her, Ann jokes) to pursue a career in science herself. She moved to the US from China for college and started studying pre-med and psychology, initially thinking she wanted to become a doctor. However, she soon found herself hooked on neuroscience after just one class. Ann was fascinated to learn how the brain generates behaviour and how much we still don’t know about this relationship. Now a group leader at the Sainsbury Wellcome Centre in London, Ann continues to pursue this early interest as she seeks to understand how neural processes support flexible decision-making at a cellular and network level.
Having discovered her passion for studying the brain in college, Ann felt that graduate school was the natural next step. She moved to Princeton for her PhD and did a couple of rotation projects in different labs before settling in the lab of Dr. Carlos Brody. At the start of her PhD, Carlos suggested she take the lead on a project studying executive control in rats. Executive control refers to the ability to carry out goal-directed behaviour using complex cognitive processes. The behavioural task in this project was inspired by a similar paradigm in primate research in which monkeys are trained to saccade towards or away from a target stimulus. In Ann’s experiment, rats were trained to orient their heads towards a stimulus in response to one auditory cue, and away from the stimulus in response to a different auditory cue. Similarly to primates, rodents display behavioural asymmetries in this task: orienting away from the stimulus is more cognitively demanding than orienting towards the stimulus, making it both a harder action to learn and slower to execute. Ann was interested in understanding how rats were able to flexibly process these different cues and select the appropriate action, and the neural basis of these behavioural asymmetries.
Ann admits it was a difficult behaviour for rats to learn and she spent a lot of her PhD optimising the training protocol. Once the rats had learned to do the task, she started exploring which brain regions underpin this complex behaviour using a combination of electrophysiology and optogenetics. As the prefrontal cortex (PFC) is known to play a key role in executive control, Ann wasn’t surprised to find that perturbing PFC hindered rats’ ability to do the task. She was surprised, however, to discover that task performance was also disrupted when she inhibited the superior colliculus (SC). The SC is a midbrain structure known to be important for transforming sensory input into motor output and coordinating eye and head-movements. Ann’s experiment demonstrated that bilateral inactivation of SC impaired animals’ ability to perform the more cognitively demanding trial type (oritentating away from a stimulus), while leaving performance on the other trial type more or less intact. This indicates that SC plays a critical role in higher order cognitive processes underpinning this behaviour, not just the motor aspects of this task. After this exciting result, the rest of Ann’s PhD then focused on exploring the role of the SC in higher order cognition.
After completing her PhD, Ann returned to China for a postdoc. Although moving back to China as a postdoc was never part of her career plan, her husband had recently been offered an exciting opportunity to start his own lab in Shanghai, and the two of them decided to make the move together. She was thrilled to find that neuroscience in Shanghai had undergone a significant expansion in recent years and there were many labs to choose from. She joined the lab of Dr. Ning-long Xu, and worked on a project that sought to understand how connections between the SC and secondary motor cortex (M2) support motor planning during decision-making. Using a combination of calcium imaging, optogenetics, and pharmacological manipulation, Ann demonstrated that SC neurons projecting to M2 encode information about the upcoming choice during motor planning and execution, and that disrupting this pathway impaired mice’s task performance during difficult or delayed decisions. In addition to expanding her experimental skillset, Ann reflects that this post-doc taught her a new way of thinking about decision-making both in the lab and in her own life. Making the decision to come back to China for her postdoc exemplified that decision-making is never black and white: one has to consider circumstance, experiences, and the thoughts and feelings of others when making choices, and it is often difficult to predict the outcome in advance.
When asked about challenges she has faced in her career, Ann reflects that becoming a mother was one of the hardest parts of her professional journey. After all, “the three body problem is even bigger than the two body problem”. She admits finding the stress and anxiety surrounding the decision to have a child, and the physical and mental recovery afterward, very challenging. Even now, it is often difficult to balance her work as a scientist with her life as a parent. Ann feels there is still a great deal of institutional and cultural change that needs to happen to make the transition to parenthood and work-life balance easier for parents in academia. Nonetheless, she feels immensely grateful to her husband for all the support he provided during this challenging time in her life and feels their decisions in the face of a great deal of uncertainty definitely worked out for the best.
Ann started her own lab at the Sainsbury Wellcome Centre just over a year ago and says this is undoubtedly the most fun stage of her career so far. She admits that the transition from postdoc to PI was a bit of a blur, but she feels very fortunate to be working in such a supportive, collaborative, and dynamic scientific environment. The goal of her lab is to understand the neural circuit mechanisms that underpin decision-making in a range of different contexts. One focus is decision-making under risk. In the real world, the outcomes associated with different choices are rarely guaranteed. As such, combining past experiences with current uncertainty is a fundamental cognitive process. Ann is training mice to choose between small certain rewards and ‘lotteries’ — larger rewards with a lower probability — to begin probing how the brain represents risk and how animals may shift their risk preference in different circumstances. Ann is also interested in social decision-making, where individuals in multi-agent/shared environments have to integrate information about past, current, and future behaviors of self and other to make decisions. As Ann has experienced herself, almost all decisions involve incorporating information about the feelings and actions of others. Ann is now trying to design behavioural paradigms to study this complex social phenomenon in mice. In this, too, the outcomes are uncertain, but considering how her own risks and difficult decisions have paid off, we are excited to see where these new and exciting projects will lead.
Find out more about Chunyu Ann and her lab’s research here.
Listen to Chunyu Ann’s full interview with Margarida on December 13, 2022 below!
