Matta Rita, Reato Davide, Lombardini Alberto, Moreau David, O'Connor Rodney P
Mines Saint-Etienne, Centre CMP, Departement BEL, F - 13541 Gardanne, France.
Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix Marseille Université, 13005 Marseille, France.
PLoS One. 2025 Apr 1;20(4):e0320376. doi: 10.1371/journal.pone.0320376. eCollection 2025.
Electrical stimulation is a powerful tool for investigating and modulating brain activity, as well as for treating neurological disorders. However, understanding the precise effects of electrical stimulation on neural activity has been hindered by limitations in recording neuronal responses near the stimulating electrode, such as stimulation artifacts in electrophysiology or obstruction of the field of view in imaging. In this study, we introduce a novel stimulation device fabricated from conductive polymers that is transparent and therefore compatible with optical imaging techniques. The device is manufactured using a combination of microfabrication and inkjet printing techniques and is flexible, allowing better adherence to the brain's natural curvature. We characterized the electrical and optical properties of the electrodes, focusing on the trade-off between the maximum current that can be delivered and optical transmittance. We found that a 1 mm diameter, 350 nm thick PEDOT:PSS electrode could be used to apply a maximum current of 130 μA while maintaining 84% transmittance (approximately 50% under 2-photon imaging conditions). We then evaluated the electrode performance in the brain of an anesthetized mouse by measuring the electric field with a nearby recording electrode and found values up to 30 V/m. Finally, we combined experimental data with a finite-element model of the in vivo experimental setup to estimate the distribution of the electric field underneath the electrode in the mouse brain. Our findings indicate that the device can generate an electric field as high as 300 V/m directly beneath the electrode, demonstrating its potential for studying and manipulating neural activity using a range of electrical stimulation techniques relevant to human applications. Overall, this work presents a promising approach for developing versatile new tools to apply and study electrical brain stimulation.
电刺激是研究和调节大脑活动以及治疗神经疾病的有力工具。然而，由于在刺激电极附近记录神经元反应存在局限性，例如电生理学中的刺激伪迹或成像中的视野阻碍，理解电刺激对神经活动的确切影响受到了阻碍。在本研究中，我们介绍了一种由导电聚合物制成的新型刺激装置，该装置是透明的，因此与光学成像技术兼容。该装置采用微加工和喷墨打印技术相结合制造而成，具有柔韧性，能够更好地贴合大脑的自然曲率。我们对电极的电学和光学特性进行了表征，重点关注可输送的最大电流与光学透过率之间的权衡。我们发现，直径为1毫米、厚度为350纳米的聚3,4-乙撑二氧噻吩：聚苯乙烯磺酸盐（PEDOT:PSS）电极可用于施加最大电流为130微安，同时保持84%的透过率（在双光子成像条件下约为50%）。然后，我们通过用附近的记录电极测量电场来评估该电极在麻醉小鼠大脑中的性能，发现电场值高达30伏/米。最后，我们将实验数据与体内实验装置的有限元模型相结合，以估计小鼠大脑中电极下方电场的分布。我们的研究结果表明，该装置可在电极正下方产生高达300伏/米的电场，证明了其使用一系列与人类应用相关的电刺激技术来研究和操纵神经活动的潜力。总的来说，这项工作为开发用于应用和研究脑电刺激的多功能新工具提供了一种有前景的方法。
