Comparing responses to visual and auditory stimuli in anesthetized and minimally restrained awake mice using quiet zero echo time MB-SWIFT fMRI

Motivation: Anesthesia is a major confounding factor for pre-clinical fMRI and thus awake fMRI protocols with minimal body restraints are needed. Goal(s): Our goal was to develop a novel motion-tolerant fMRI approach for awake mice and to compare sensory responsiveness between awake and anesthetized mice. Approach: Following a 14-day habituation protocol, mice were imaged using zero-echo-time MB-SWIFT fMRI with visual and auditory stimulation schemes in awake state and under ketamine-xylazine anesthesia. Results: In awake mice, the activation of all key nodes was detected after both sensory stimuli. However, anesthesia suppressed particularly the auditory responses and affected the fMRI response shapes. Impact: Awake animal imaging has gained much popularity in recent preclinical studies. Together with quiet and motion-tolerant MB-SWIFT imaging our approach has potential for more complex behavioral fMRI designs that improve our understanding of neuroscience and support translational drug discovery.