Norepinephrine links astrocytic activity to regulation of cortical state

Cortical state, defined by population-level neuronal activity patterns, determines sensory perception. While arousal-associated neuromodulators—including norepinephrine (NE)—reduce cortical synchrony, how the cortex resynchronizes remains unknown. Furthermore, general mechanisms regulating cortical synchrony in the wake state are poorly understood. Using in vivo imaging and electrophysiology in mouse visual cortex, we describe a critical role for cortical astrocytes in circuit resynchronization. We characterize astrocytes’ calcium responses to changes in behavioral arousal and NE, and show that astrocytes signal when arousal-driven neuronal activity is reduced and bi-hemispheric cortical synchrony is increased. Using in vivo pharmacology, we uncover a paradoxical, synchronizing response to Adra1a receptor stimulation. We reconcile these results by demonstrating that astrocyte-specific deletion of Adra1a enhances arousal-driven neuronal activity, while impairing arousal-related cortical ..., Recording setup
Animals were given at least 1 week after surgery for recovery and viral expression. They were then habituated on a custom-made circular running wheel over at least two days, and for a cumulative time of at least 2.5 hours, before experimental recordings began. After habituation, mice were head-fixed on the wheel and movements were recorded by monitoring deflections of colored tabs on the edge of the wheel using an optoswitch (Newark, HOA1877-003). 
Pupillometry
Pupil recordings were made using a Genie near-infrared (NIR) camera (1stVision, M640), a telescopic lens (Thorlabs, MVL50TM23), and acquired at 30Hz using the MATLAB Image Acquisition toolbox. A small monitor (Amazon, B06XKLNMW3) showing a consistent teal background color (RGB: 0,1,1) was placed by the mouse to allow for observation of the full range of pupil dynamics in an otherwise dark room. For experiments without imaging, a NIR light (Amazon, B00NFNJ7FS) was used to visualize the pupil.
Two-photon imaging
Two..., All data are two-photon imaging, electrophysiology, and associated physiology datasets. All data is formatted to allow for reconstructing the figures in Reitman et al. 2022 with limited user input needed. Data are stored as MAT-Files and the linked code was generated in MATLAB 2020a. The data for each figure is separated into individual MAT-Files, and should be placed in the same folder as the linked code.  Running the ‘MakeFigures.m’ file will result in all Paper figures being created, and to create individual figures one can run the ‘PlotFigX.m’ function within ‘MakeFigures.m’. Abbreviations used in file names: xcorr = cross-correlation; ETA = event-triggered average; floxed = Adra1afl/fl