91ÌÒÉ«

Abstract

Detecting minuscule electrical activity of cell populations is a major challenge to electrophysiologists. To overcome such challenge, we built a highly sensitive measuring setup. The setup comprises a biosensor based on a metal/Si/SiO2/interdigitated gold electrode. Interferences were minimized with adequate shielding. To validate the extreme sensitivity of the measuring system, we investigated the electrical activity of large populations of two cell lines known to be electrically quiescent. The cell lines studied were the human cervix carcinoma cell line, HeLa and C6 glioma cells. HeLa cells are supposed to be electrically quiet as they don�t originate from the brain or any other electrically excitable tissue. However, due to the high sensitivity of our measurement system, even the HeLa cells demonstrate fluctuations of their basal current level, which is much higher in amplitude than the background acquisition noise. The low frequency analysis of the HeLa cells reveals clear current fluctuations of about 3 pA. Measurement of glioma cells subtle electrical activity is typically hampered by the high background noise. Here, we detect glioma electrical behavior without any physical disruption or interference into their physiology. The current noise analysis, performed with the sensing system determined that the glioma cell activity is primarily caused by the opening of voltage gated Na+ and K+ ion channels and can be efficiently abolished using specific pharmacological inhibitors. We present here a unique tool to study the electrophysiological properties of large cell populations as an in vitro reference for tumor bulks in vivo.

Biography

Paulo Roberto Ferreira da Rocha has completed his PhD from University of Algarve, Portugal, in 2014. Since 2014, he has been a Postdoctoral Researcher at Max Planck Institute for Polymer Research in Mainz, Germany.

Email: paulorfdrocha@gmail.com