Graphene fibre microelectrodes with little-to-no image artifact have been developed, allowing for simultaneous deep brain stimulation and functional magnetic resonance imaging.
Simultaneous deep brain stimulation (DBS) and functional magnetic resonance imaging (fMRI) can provide valuable insights into brain function, connectivity patterns, and therapeutic mechanisms of various neurological disorders. However, due to a mismatch in magnetic susceptibility between conventional DBS electrodes and water/tissues, the electrodes elicit strong magnetic field interference and produce significant artifacts in the MRI images. This is particularly severe in fMRI, as it is more susceptible to such effect.
Recently, collaboration between Dr. Duan Xiaojie's group (Department of Biomedical Engineering, College of Engineering, Peking University) and Dr. Liang Zhifeng's group (Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences) has led to an MRI-compatible, graphene fibre (GF) microelectrode. Using a Parkinson鈥檚 disease (PD) rat model, this electrode achieved full activation pattern mapping by simultaneous DBS and fMRI.
High-frequency DBS targeted at the subthalamic nucleus (STN) with GF electrodes effectively alleviated motor deficits in rats with PD, according to the paper published in Nature Communications. Moreover, the little-to-no image artifact of the GF electrodes made all brain regions accessible by fMRI mapping under simultaneous DBS, the authors claimed.
They also reported that STN鈥揇BS in PD rats with GF microelectrodes evoked robust blood-oxygenation-level-dependent (BOLD) responses in multiple cortical and subcortical regions along the basal ganglia鈥搕halamocortical network in a frequency-dependent manner. The BOLD responses of some of these regions were not previously detectable with traditional metal electrodes due to their large artifact, highlighting the usefulness of their invention.