Effect of Jet Lag on Brain White Matter Functional Connectivity

Background: A long haul flight across more than five time zones may produce a circadian rhythm sleep disorder known as Jet Lag. Little is know about the effect of Jet Lag on white matter (WM) functional connectivity (FC). Methods: Resting-state functional Magnetic Resonance Imaging was performed in 23 participants within 24 hours of flying and again 50-days later. Gray (GM) and WM networks were identified by K-means clustering. WM FC and Functional Covariance Connectivity (FCC) analyzed. Next, a sliding window method was used to establish dynamic WM FC. WM static and dynamic FC and FCC were compared between when participants had initially completed their journey and 50-days later. Emotion was assessed by using the Positive and Negative Affect Schedule and the State Anxiety Inventory. All subjects were confirmed to have experienced Jet Lag by the Columbian Jet Lag Scale. Findings: The static FC of WM7-GM7, and WM14-GM4, were lower after the long haul flight compared with recovery. Corresponding results were obtained for the dynamic FC analysis. FCC between the cingulate network (WM7) and several brain networks was weaken and especially precentral/postcentral network. Emotion scores were negatively correlated with the FC between the WM7 and sensorimotor related regions. Interpretation: The results of this study provide further evidence for the existence of WM networks and show that Jet Lag is associated with alterations in static and dynamic WM FC and FCC especially in sensori-motor networks. Jet Lag is a complex problem which not only related with sleep rhythm but also influence emotion. Funding Statement: This study was supported by the National Natural Science Foundation (Grant Nos. 81971595, 81771812, 81761128023 and 81621003). Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT, Grant No. IRT16R52) of China, and the Science and Technology Department of Sichuan Province (2018SZ0391) and the Innovation Spark Project of Sichuan University (No. 2019SCUH0003). Declaration of Interests: The authors have no conflict of interest to declare. Ethics Approval Statement: The study was approved by the West China Hospital Ethics Committee of Sichuan University and prior to any investigations being performed each subject gave fully informed written consent of their willingness to participate.