Glymphatic Diffusion-Weighted MRI in Awake Mice: Comparison to Anesthetized Brain States.

Motivation: This study investigates the glymphatic function in awake vs. anesthetized mice by means of diffusion-weighted (DW) MRI. Goal(s): Application of developed ‘silent’ DW-MRI protocol is presented for comparison of awake and anesthetized mice under ketamine-xylazine (K/X), and isoflurane. Approach: In total, n=17 C57BL/6 mice were habituated to awake MRI setup, and successfully underwent DW-MRI with monitored body temperature and respiratory rate. Results: Results showed that brain water mobility in awake mice was consistent, while K/X and isoflurane affected both slow and fast MR diffusivity measures differently. Awake DW-MRI offers a promising alternative to MRI under anesthesia, promoting increased biological relevance and translational potential. Impact: This research on glymphatic function using DW-MRI underscores the importance of non-invasive MRI in awake mice, emphasizing anesthesia's impact on physiological stability. It highlights the translational potential of awake DW-MRI and is of importance to neuroscientific and biomedical research communities.