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

• Published in: Sensors and actuators. B, Chemical Vol. 320; p. 128442
• Main Authors: Idogawa, Shinnosuke, Yamashita, Koji, Kubota, Yoshihiro, Sawahata, Hirohito, Sanda, Rioki, Yamagiwa, Shota, Numano, Rika, Koida, Kowa, Kawano, Takeshi
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.10.2020; Elsevier Science Ltd
• Subjects: Coaxial cables; Differential geometry; Differential recording; Electrodes; Microelectrode; Multichannel recording; Needles; Neural recording; Recording; Signal quality; Signal to noise ratio; Microelectrode; Multichannel recording; Neural recording; Differential recording
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.128442

•We fabricated a <10-μm diameter coaxial microneedle-electrode.•Applications include multichannel and local-differential neuronal recordings.•LFP and unit-activity were recorded from the mouse’s cortex in vivo.•SNR and firing rate were increased by the local-differential recording. 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.