Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv 69978, Israel.
J Neural Eng. 2011 Oct;8(5):056008. doi: 10.1088/1741-2560/8/5/056008. Epub 2011 Aug 12.
Simultaneous calcium imaging and extra-cellular recordings from cultured cortical rat neurons were performed to directly map the efficacy of extra-cellular recordings with microelectrodes. For the first time, we can associate extra-cellular recordings with neuronal activity of specific neurons in the vicinity of the electrode. We demonstrate that recorded cells can be identified by correlating the electrical signals and the calcium response. Our data demonstrate that in sparse cultures, microelectrodes record exclusively from cells which reside at very close proximity to the recording electrode. Moreover, we show that recording appears to be limited to only a partial subset of the cells residing in this range. We further show that even in cases of strong neuron-electrode coupling, extra-cellular signals recorded from single, well-identified neurons vary in shape over time rendering spike sorting and network activity rate analysis incongruous. As multi-electrode array technology is becoming increasingly widespread, the visualization technique we report here will help users better understand the limits of this versatile and useful method.
对培养的皮质大鼠神经元进行钙成像和细胞外记录，以直接绘制微电极细胞外记录的效果。我们首次可以将细胞外记录与电极附近特定神经元的神经元活动相关联。我们证明，通过将电信号和钙反应进行相关联，可以识别记录的细胞。我们的数据表明，在稀疏培养物中，微电极仅记录与记录电极非常接近的细胞。此外，我们表明记录似乎仅限于该范围内的细胞的一小部分。我们进一步表明，即使在神经元-电极耦合很强的情况下，从单个明确鉴定的神经元记录的细胞外信号在形状上也随时间变化，从而使尖峰排序和网络活动率分析不一致。随着多电极阵列技术的日益普及，我们在这里报告的可视化技术将帮助用户更好地了解这种多功能且有用的方法的局限性。
