Neural Excitations by the Current Injected Through the Carbon Nanotube Surface of an Intracortical Electrode in Vivo

We fabricated carbon-nanotube-coated neural electrodes that can be inserted into the cerebral cortex in vivo. Using the fast voltage-sensitive dye imaging technique, we visualized spatio-temporal neural responses in the mouse cortex to microstimulation delivered through these electrodes. The experimental results showed the usability of the electrodes for inducing spatially confined neural excitations in vivo. This type of stimulation electrode is expected to have higher charge conductivity and cell membrane affinity at the electrode-tissue interface as the coating layer of the carbon nanotube becomes thicker while maintaining the geometric cross-sectional area. This might offer an advantage over the conventional metal-surface electrode.