Imaging Brain Activity: Longitudinal FMRI in Mice Using Medetomidine Sedation

Joanna Magdalena Adamczak¹, Tracy Deanne Farr¹, Joerg Ulrich Seehafer¹, Mathias Hoehn¹

In this study we present the successful establishment of a non-invasive medetomidine based protocol for longitudinal fMRI studies of brain activity in mice. The optimal dose of medetomidine was evaluated with regard to sufficient sedation, tolerance by the animal and preservation of electrical activity in the brain. For this purpose transcutaneous CO₂ and somatosensory evoked potentials (SSEP) were measured. Following electrical forepaw stimulation we observed brain activity in the contralateral somatosensory cortex using blood oxygenation level-dependent (BOLD) contrast with gradient echo EPI images at 7.0T and 11.7T.