Lee Daae, Moon Hyeong Cheol, Tran Bao-Tram, Kwon Dae-Hyuk, Kim Yong Hee, Jung Sang-Don, Joo Jong Hoon, Park Young Seok
Department of Advanced Materials Engineering, Chungbuk National University, Cheongju 28644, Korea.
Department of Neurosurgery, Chungbuk National University Hospital, Cheongju 28644, Korea.
Exp Neurobiol. 2018 Dec;27(6):593-604. doi: 10.5607/en.2018.27.6.593. Epub 2018 Dec 5.
Tetrodes, consisting of four twisted micro-wires can simultaneously record the number of neurons in the brain. To improve the quality of neuronal activity detection, the tetrode tips should be modified to increase the surface area and lower the impedance properties. In this study, tetrode tips were modified by the electrodeposition of Au nanoparticles (AuNPs) and dextran (Dex) doped poly (3,4-ethylenedioxythiophene) (PEDOT). The electrochemical properties were measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A decrease in the impedance value from 4.3 MΩ to 13 kΩ at 1 kHz was achieved by the modified tetrodes. The cathodic charge storage capacity (CSC) of AuNPs-PEDOT deposited tetrodes was 4.5 mC/cm, as determined by CV measurements. The tetrodes that were electroplated with AuNPs and PEDOT exhibited an increased surface area, which reduced the tetrode impedance. recording in the ventral posterior medial (VPM) nucleus of the thalamus was performed to investigate the single-unit activity in normal rats. To evaluate the recording performance of modified tetrodes, spontaneous spike signals were recorded. The values of the L-ratio, isolation distance and signal-to-noise (SNR) confirmed that electroplating the tetrode surface with AuNPs and PEDOT improved the recording performance, and these parameters could be used to effectively quantify the spikes of each cluster.
由四根绞合微丝组成的四极管能够同时记录大脑中的神经元数量。为了提高神经元活动检测的质量，应改进四极管尖端以增加表面积并降低阻抗特性。在本研究中，通过电沉积金纳米颗粒（AuNPs）和掺杂葡聚糖（Dex）的聚（3,4-乙撑二氧噻吩）（PEDOT）对四极管尖端进行了修饰。使用电化学阻抗谱（EIS）和循环伏安法（CV）测量电化学性质。修饰后的四极管在1 kHz时阻抗值从4.3 MΩ降至13 kΩ。通过CV测量确定，沉积有AuNPs-PEDOT的四极管的阴极电荷存储容量（CSC）为4.5 mC/cm²。电镀有AuNPs和PEDOT的四极管表现出表面积增加，这降低了四极管阻抗。在丘脑腹后内侧（VPM）核中进行记录以研究正常大鼠的单单位活动。为了评估修饰后四极管的记录性能，记录了自发尖峰信号。L比率、隔离距离和信噪比的值证实，用AuNPs和PEDOT电镀四极管表面可提高记录性能，并且这些参数可用于有效量化每个簇的尖峰。
