Coaxial microneedle-electrode for multichannel and local-differential recordings of neuronal activity

摘要

Electrophysiological recording requires low invasive electrode geometry in the tissue and high-quality signal acquisitions. Here we propose a ＜ 10-μm diameter coaxial cable-inspired needle electrode, which consists of a core electrode in the needle surrounded by another shell electrode. The neuronal recording capability of these electrodes was confirmed by multichannel recording of a mouse cortex in vivo. Given that the shell electrode played the role of a reference electrode, the coaxial electrode also enabled a differential recording at the local area within the tissue. Compared to the recording without the referenced shell electrode, the differential recording demonstrated a twofold higher signal-to-noise ratio, while the firing rate increased. These results suggest that the coaxial microneedle-electrode will provide high-quality neuronal signals in electrophysiological recordings including ex vivo and in vitro applications, similar to the in vivo recording.