Max-Planck-Institute for Biological Cybernetics, Department of Physiology of Cognitive Processes, Spemannstrasse 38, 72076 Tübingen, Germany.
J Neurosci Methods. 2013 May 30;216(1):43-8. doi: 10.1016/j.jneumeth.2013.03.017. Epub 2013 Mar 31.
Understanding the principles that underlie information processing by neuronal networks requires simultaneous recordings from large populations of well isolated single units. Twisted wire tetrodes (TWTs), typically made by winding together four ultrathin wires (diameter: 12-25 μm), are ideally suited for such population recordings. They are advantageous over single electrodes; both with respect to quality of isolation as well as the number of single units isolated and have therefore been used extensively for superficial cortical recordings. However, their limited tensile strength poses a difficulty to their use for recordings in deep brain areas. We therefore developed a method to overcome this limitation and utilize tetrodes for electrophysiological recordings in the inferotemporal cortex of rhesus macaque. We fabricated a novel, stiff tetrode called the tube tetrode (TuTe) and developed a multi-tetrode driving system for advancing up to 5 TuTes through a ball and socket chamber to precise locations in the temporal lobe of a rhesus macaque. The signal quality acquired with TuTes was comparable to conventional TWTs and allowed excellent isolation of multiple single units. We describe here a simple method for constructing TuTes, which requires only standard laboratory equipment. Further, our TuTes can be easily adapted to work with other microdrives commonly used for electrophysiological investigation in the macaque brain and produce minimal damage to the cortex along its path because of their ultrathin diameter. The tetrode development described here could allow studying neuronal populations in deep lying brain structures previously difficult to reach with the current technology.
了解神经元网络信息处理的原理需要同时从大量分离良好的单个单元中进行记录。扭线四极管（TWTs）通常由四条超细线（直径：12-25μm）缠绕而成，非常适合进行这种群体记录。与单个电极相比，它们具有优势；无论是在隔离质量还是隔离的单个单元数量方面，因此已被广泛用于浅层皮质记录。然而，它们有限的拉伸强度给深部脑区的记录带来了困难。因此，我们开发了一种方法来克服这一限制，并利用四极管进行恒河猴颞叶下区的电生理记录。我们制造了一种新型的、刚性的四极管，称为管四极管（TuTe），并开发了一种多四极管驱动系统，该系统可将多达 5 个 TuTe 通过球窝室推进到恒河猴颞叶的精确位置。使用 TuTe 获得的信号质量与传统 TWTs 相当，并允许对多个单个单元进行出色的隔离。我们在这里描述了一种简单的 TuTe 构建方法，仅需标准实验室设备。此外，我们的 TuTe 可以很容易地适应其他常用于恒河猴大脑电生理研究的微驱动器，并由于其超细线径，在其行进过程中对皮层造成的损伤最小。这里描述的四极管开发可以使研究以前难以通过现有技术到达的深层脑结构中的神经元群体成为可能。
