Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Xin-Wei Tang
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Yue Cao
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Hua-Teng Cao
Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
Wei Zhang
Institute of Brain Science, Fudan University, Shanghai, China
Jun-Fa Wu
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Yu-Lian Zhu
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Ying Chen
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Yi Lin
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Yi Wu
Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental HealthCenter, Shanghai Jiaotong University School of Medicine, Shanghai, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China; Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People’s Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
Sleep is essential in maintaining physiological homeostasis in the brain. While the underlying mechanism is not fully understood, a ‘synaptic homeostasis’ theory has been proposed that synapses continue to strengthen during awake and undergo downscaling during sleep. This theory predicts that brain excitability increases with sleepiness. Here, we collected transcranial magnetic stimulation measurements in 38 subjects in a 34 hr program and decoded the relationship between cortical excitability and self-report sleepiness using advanced statistical methods. By utilizing a combination of partial least squares regression and mixed-effect models, we identified a robust pattern of excitability changes, which can quantitatively predict the degree of sleepiness. Moreover, we found that synaptic strengthen occurred in both excitatory and inhibitory connections after sleep deprivation. In sum, our study provides supportive evidence for the synaptic homeostasis theory in human sleep and clarifies the process of synaptic strength modulation during sleepiness.
