Institute of Neuroinformatics, ETH Zurich & University of Zurich, Zurich, Switzerland.
Neuroscience Center Zurich, University of Zurich & ETH Zurich, Zurich, Switzerland.
Nat Commun. 2024 Jun 6;15(1):4822. doi: 10.1038/s41467-024-49226-9.
We introduce Ultra-Flexible Tentacle Electrodes (UFTEs), packing many independent fibers with the smallest possible footprint without limitation in recording depth using a combination of mechanical and chemical tethering for insertion. We demonstrate a scheme to implant UFTEs simultaneously into many brain areas at arbitrary locations without angle-of-insertion limitations, and a 512-channel wireless logger. Immunostaining reveals no detectable chronic tissue damage even after several months. Mean spike signal-to-noise ratios are 1.5-3x compared to the state-of-the-art, while the highest signal-to-noise ratios reach 89, and average cortical unit yields are ~1.75/channel. UFTEs can track the same neurons across sessions for at least 10 months (longest duration tested). We tracked inter- and intra-areal neuronal ensembles (neurons repeatedly co-activated within 25 ms) simultaneously from hippocampus, retrosplenial cortex, and medial prefrontal cortex in freely moving rodents. Average ensemble lifetimes were shorter than the durations over which we can track individual neurons. We identify two distinct classes of ensembles. Those tuned to sharp-wave ripples display the shortest lifetimes, and the ensemble members are mostly hippocampal. Yet, inter-areal ensembles with members from both hippocampus and cortex have weak tuning to sharp wave ripples, and some have unusual months-long lifetimes. Such inter-areal ensembles occasionally remain inactive for weeks before re-emerging.
我们介绍了超灵活触手电极 (Ultra-Flexible Tentacle Electrodes, UFTEs)，它采用机械和化学固定相结合的方式，在不限制插入深度的情况下，将许多独立纤维封装到尽可能小的空间内。我们展示了一种方案，可以将 UFTEs 同时植入到任意位置的多个大脑区域，而不会受到插入角度的限制，并展示了一个 512 通道的无线记录器。免疫染色显示，即使在几个月后，也没有可检测到的慢性组织损伤。与现有技术相比，平均尖峰信号噪声比提高了 1.5-3 倍，最高信号噪声比达到 89，平均皮质单元产量约为 1.75/通道。UFTEs 可以在至少 10 个月的时间内（测试的最长时间）跨多个会话跟踪相同的神经元。我们从自由活动的啮齿动物的海马体、后穹窿皮质和内侧前额叶皮层中同时跟踪了跨区域和区域内的神经元集合体（在 25 毫秒内重复激活的神经元）。平均集合体寿命短于我们可以跟踪单个神经元的时间。我们确定了两种不同类型的集合体。那些对尖峰波涟漪有调谐的集合体寿命最短，其成员主要来自海马体。然而，来自海马体和皮质的成员组成的跨区域集合体对尖峰波涟漪的调谐较弱，并且有些具有不寻常的长达数月的寿命。这种跨区域集合体偶尔会在重新出现之前几周保持不活跃状态。
