Functional imaging evidence for task-induced deactivation and disconnection of a major default mode network hub in the mouse brain
Proceedings of the National Academy of Sciences of the United States of America June 15, 2020 J. Ferrier, E. Tiran, T. Deffieux et al.
Functional ultrasound imaging, which offers higher sensitivity and spatiotemporal resolution than fMRI, was validated for studying sensory stimulation-induced changes in the awake mouse brain. Using this approach in lightly sedated conscious mice, unilateral whisker stimulation activated the contralateral barrel cortex and reduced activity in the ipsilateral barrel cortex via interhemispheric inhibition, while also increasing bilateral hippocampal connectivity. During awake resting-state periods, whisker stimulation specifically reduced activation and interhemispheric correlation in the retrosplenial cortex, a major hub of the default mode network (DMN). These findings provide functional evidence for an evolutionarily preserved DMN function in mice, supporting the translational relevance of this preclinical model for neuropsychiatric diseases.