State-transition fMRI between anesthetized and awake mice

Motivation: State-transition brain dynamics underlie the loss or regaining of consciousness, which is central to studies of anesthesia, sleep, and coma. It remains challenging to provide robust statistical estimates of brain state transition maps with fMRI. Goal(s): Specify transitionary brain state-dependent rs-fMRI signal changes between awake and anesthetized mice. Approach: fMRI with respiratory monitoring and real-time pupillometry are used to investigate bandwidth-specific functional connectivity changes as animals transition into and out anesthetized states. Results: Bandwidth-specific coherence spatial patterns highlights neuromodulatory centers located at brainstems, as well as the retrosplenial and anterior cingulate area and central thalamic nuclei with higher coherence in transitional states. Impact: Distinct brain regions along reticular ascending pathways can be directly identified by analyzing the spectral-specific rs-fMRI signal changes that occur as animals transition into and out of anesthetized states. This work opens a new avenue for consciousness studies in rodents.