摘要目的 探讨清醒状态下丘脑底核(STN)长期在体多通道单细胞放电记录新技术.方法 采用自行设计的集束式微电极阵列记录STN单细胞放电情况.设计主要由3部分构成:(1)29号皮下注射用不锈钢管为引导管固定电极丝,并作为脑组织接地电极;(2)5根20 μm铂铱合金丝作为记录电极,1根50.8 μm不锈钢合金丝作为局部参考电极,电极尖端呈“路标手”样排列,聚乙二醇固定；(3)带有螺丝旋紧的连接器减少实验动物自由活动带来的信号伪迹.将这种电极用于6只正常清醒大鼠STN单细胞放电记录,评价术后5周内的STN单细胞放电单位的记录稳定性. 结果 术中记录到27个STN放电单位,70.4％(19/27)存活超过2d;5周内记录到9个新生放电单位.术后峰峰波幅与时间之间无显著线性相关性(r=-0.047,P=o.655)；并且信噪比维持稳定,其与峰峰波幅间存在显著线性相关(r=0.934,P=0.000).电极植入3周,仍有超过50％的细胞保留率.相同神经元75％波形相似系数大于0.90. 结论 本研究设计的微电极阵列在记录活动状态下STN单细胞放电时,波形特征稳定,细胞保留率理想,适用于慢性清醒状态在体STN多通道单细胞放电的电生理记录.

abstractsObjective To introduce a bundled microelectrode array of chronic in vivo single-unit recording in subthalamie nucleus (STN) of freely behaving rats. Methods STN single cell discharge was recorded by a self-designed bundled microelectrode array.Our microelectrode array design consisted of 3 parts:(1) a 29-guage stainless steel tube was served as a guide tube to facilitate the brain penetration of microwire tips,and as a ground electrode of the brain tissues as well. (2) Five 20μm platiniridium wires were used as recording electrodes and a 50.8 μm stainless steel wire with 1 mm bare tip was employed as local potential reference; all the above resembled a guiding-hand-shaped arrangement in microwire tips,and was fixed by trny plot of carbowax moreover.(3) A male connector with end screw receptors was employed to make the array connection more stable so as to minimize the movement artifacts; six normal rats were implanted with this kind of electrode arrays,and the stability of STN single-unit recording was evaluated in the following 5 weeks. Results Twenty-seven firing units were captured during operation,of which 70.4％ (19/27) survived more than 2 d,and 9 new units were acquired within 5 weeks.No significant linear correlation of peak-to-peak amplitude was noted between each 2 different recording sections (Pearson r=-0.047,P=0.655),and whilst signal-to-noise ratio was stable with significant correlation to peak-to-peak amplitude (r=0.934,P=0.000).More than half of the initial acquired STN units retained more than 3 weeks. And there were more than 75％ r values of waveform similarities large than 0.90 of the same units across different periods. Conclusion This methodology may be appreciated for STN long-term single-unit recording with stable recording quality and favorable cell retained rate.