Resting state functional MRI (rs-fMRI) is a method of functional brain imaging that can be used to evaluate regional interactions that occur when a subject is not performing a specific task. These interactions are observed through changes in the blood flow in the brain, creating a blood oxygen level dependent (BOLD) signal. Rs-MRI detects low frequency fluctuations of BOLD signal and their temporal correlations. The technique provides a non-invasive window into the intrinsic whole brain functional connectivity architecture, moving away from localizing isolated functional brain areas. .
Rs-MRI is used extensively in human brain investigations and while the characterization of consistent and robust resting state networks in rodents is progressively evolving, fine-grained mapping of the mouse brain resting state networks remains an underexplored area. This is in contrast to the widespread use of this specie in experimental neuroscience for modeling human neurological disorders. Therefore, uncovering information related to the remodeling of brain networks in these models could contribute to a change in the view on brain disorders pathophysiology and finally establishing imaging biomarkers. A major challenge of rs-fMRI in small animals is the difficulty of achieving fast acquisition methods at high resolution while ensuring stable physiological parameters throughout the experiment. In this study, we demonstrate use of the CryoProbe, the latest technology for mouse MRI that provides a signal to noise increase of >2. This is achieved by the cooling of the probe and its electronics, making it possible to gain a fine-grained, non-invasive insight into the mouse brain functional “connectome”.