Date & Time
Time: 3:00-4:00 pm (CST), Nov.17th
Venue: IB 3106
Zoom ID: 715 337 7467
*Light refreshments will be provided
Dr. Danqian Liu
The principal investigator and doctoral supervisor at the Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences.
Wakefulness, rapid eye movement (REM) sleep, and non–rapid eye movement (NREM) sleep are characterized by distinct electroencephalogram (EEG), electromyogram (EMG), and autonomic profiles. Using automated analysis of mouse behavior, our recent works have uncovered novel subcortical and cortical mechanisms coordinating these changes for sleep regulation. Using a combination of a deep-learning algorithm for automated analysis of mouse behavior, cell type-specific electrophysiological recording, optogenetic manipulation, and virus-mediated circuit tracing, we discovered that sleep–wake brain states and motor behaviors are coregulated by shared neurons in the substantia nigra pars reticulate (SNr). These GABAergic neurons integrate wide-ranging inputs and innervate multiple arousal-promoting and motor-control circuits through extensive collateral projections, actively repressing movement for NREM sleep generation. Using facial expression analysis, we identified two distinct REM sleep substages, characterized by contrasting facial movement and autonomic activity and by distinguishable electroencephalogram theta oscillations. By performing cortex-wide calcium imaging, we found that REM sleep is accompanied by highly patterned cortical activity waves, with the retrosplenial cortex (RSC) as a major initiation site. Two-photon imaging of layer 2/3 pyramidal neurons of the RSC revealed two distinct patterns of population activities during REM sleep, encoding the two sequential REM sleep substages. Closed-loop optogenetic inactivation of RSC during REM sleep further highlights the important role of the RSC in dictating cortical dynamics and regulating REM sleep progression.
Dr. Danqian Liu got her bachelor’s degree from the University of Science and Technology of China (USTC) in 2010. In 2016, she completed her Ph.D. with Dr. Mu-Ming Poo at the Institute of Neuroscience, Chinese Academy of Sciences, studying synaptic plasticity underlying fear memory. From 2016 to 2020, she got her postdoctoral training with Dr. Yang Dan at the University of California, Berkeley. Currently, Danqian is a principal investigator and doctoral supervisor at the Center for Excellence in Brain Science and Intelligent Technology, Chinese Academy of Sciences. Her main researches focus on the functions of sleep and dreams. As a first or corresponding author, she has published multiple research articles or reviews, including Nature Neuroscience (2022, 2016), Trends in Neurosciences (2023), Science (2020), Annual Review of Neuroscience (2019).