Hemodynamic-based Mapping of Neural Activity in Medetomidine-sedated Rats using a 1.5T Compact Magnetic Resonance Imaging System: A Preliminary Study.

The use of compact magnetic resonance (MR) systems for the neuroimaging of small animals is spreading. We investigated the potential of such systems in functional MR imaging (fMRI) of somatosensory cortex activity elicited by forepaw stimulation in medetomidine-sedated rats. Using a 1.5-tesla compact imager, we detected maximum activity with an electrophysiologically optimized frequency of 9 Hz in 3 appropriately sedated rats. With this compact system, we successfully mapped neural activity by combining optimum stimulation for a large hemodynamic response with appropriate anesthesia, thus demonstrating the utility of such systems in hemodynamic-based fMRI in preclinical and translational research.