Single-channel Read-out Device for Extracellular Signal Detection of Neuronal Cell Cultures =

In vitro electroanalytical experiments through multi-electrode arrays (MEAs) are applied to observe the extracellular behaviour of excitable cells and screen the effect of specific chemical modulators and drug injections. MEAs are usually interfaced with an electronic interface consisting of a preamplification stage and a filtering one. In this project, a preamplification stage on a printed circuit board is designed for amplifying a single-channel of the available 16 electrodes of a Micro-Graphitic Single Crystal Diamond Multi-Electrode Array (μG-SCD MEA) chip, realized by the University of Torino. Thus, this read-out device provides essential tools for a future device blending and optimizing the single channel's preamplifier to all the μG-SCD MEA's available electrodes. Specifically, the μG-SCD MEA's system devotes to investigating the extracellular signals from mice's midbrain neurons through two electroanalytical recordings: amperometry and potentiometry. Single-cell amperometry allows the detection of quantal fusion events, while potentiometric measurements, the spontaneous electrical activity. Moreover, specific monophasic or biphasic stimulation patterns can be sent through a NI DAQ to the cell culture, triggering the neurons' activity. To select the experimental configuration (recording and stimulation), post-process, visualize and save the recorded data, a LabVIEW interface is implemented. Overall, in addition to the preamplifier, an active filtering stage for the single-channel and noise analysis of the electronic system are introduced to find the system's critical issues. The simulation's results performed with the MEA's electrodes submerged in a physiological solution demonstrated that the noise bandwidth has to be improved, particularly in the amperometric configuration. In contrast, it should fit in the potentiometric one. However, the device's performances have still to be adequately tested on neuronal cell cultures: just an amperometric application on cell lines (PC12) was performed. Once the main expedients showed in this work are extended to all the available electrodes, the researchers could use the read-out device to screen the midbrain cells' activity, applying both electroanalytical measurements approximately simultaneously from any μG-SCD MEA's electrode.