title: Single 5 μm diameter needle electrode block modules for unit recordings in vivo.
abstract: Investigations into mechanisms in various cortical areas can be greatly improved and supported by stable recording of single neuronal activity. In this study, fine silicon wire electrodes (diameter 3 μm, length 160 μm) are fabricated by vapor-liquid-solid (VLS) growth with the aim of stabilizing recording and reducing the invasiveness on the measurement procedure. The electrode is fabricated on a modular 1 ×  1 mm2conductive silicon block that can be assembled into a number of different device packages, for example on rigid or flexible printed circuit boards (PCB). After plating with a 5 μm diameter platinum black, the needle exhibits an electrical impedance of ~100 kΩ at 1 kHz in saline. The in vivo recording capability of the device is demonstrated using mice, and spike signals with peak-to-peak amplitudes of 200-300 μV in the range 0.5-3 kHz are stably detected, including single-unit activities in cortical layer 2/3. In addition, the device packaged with a flexible PCB shows stable unit recordings for 98.5 min (n = 4). Consequently, our modular, low-invasive needle electrode block devices present an effective route for single-unit recordings in vivo, as well as demonstrating adaptability in device design for a diverse range of experiments.
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: H
authors: H
authors: Sawahata
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: S
authors: S
authors: Yamagiwa
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: A
authors: A
authors: Moriya
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: T
authors: T
authors: Dong
authors: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: H
authors: H
authors: Oi
authors: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: Y
authors: Y
authors: Ando
authors: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.|Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: R
authors: R
authors: Numano
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.|Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: M
authors: M
authors: Ishida
authors: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.|Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi 441-8580, Japan.
authors: K
authors: K
authors: Koida
authors: Department of Electrical and Electric Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka Tempaku-cho, Toyohashi, 441-8580 Japan.
authors: T
authors: T
authors: Kawano
mesh_terms: D000818:Animals; D017097:Electric Impedance; D004567:Electrodes, Implanted; D004867:Equipment Design; D008297:Male; D051379:Mice; D008839:Microelectrodes; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D059010:Single-Cell Analysis / Q000295:instrumentation* / Q000379:methods; D013003:Somatosensory Cortex / Q000502:physiology*; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*