Zero echo time MB-SWIFT fMRI in rat spinal cord during hind paw stimulation - correlation with electrical activity

Motivation: Zero echo time MB-SWIFT fMRI is an excellent tool for spinal cord studies due to its minimal sensitivity to susceptibility artefacts and motion, however, its correlation with electrical activity has not been established. Goal(s): To determine the spatial and temporal characteristics of MB-SWIFT fMRI response in spinal cord and its dependence on neuronal activity. Approach: MB-SWIFT fMRI and electrical responses were simultaneously recorded from the rat spinal cord during electrical stimulation of a hind paw under urethane anesthesia. Results: Robust fMRI and electrical responses were measured during hind-paw stimulation. The two signals were correlated similarly to what has been observed in the brain. Impact: MB-SWIFT fMRI provides a valuable experimental tool for assessing stimulation evoked response in the spinal cord, validated here to have good agreement with electrical activity.