Mea1060 inv bc amplifier

Recordings were performed as described in Rodriguez et al. (2018 (link)). Briefly, neurons were cultured on standard MEAs containing 59 recording and 1 internal reference planar electrodes, each with a 10 μm diameter and an interelectrode spacing of 200 μm (60MEA200/10iR-Ti-gr; Multi Channel Systems, Germany). Baseline recordings were performed on DIV10 followed by lentiviral transduction with GFP, cypin, or cypinΔPDZ constructs, and recordings were taken again on DIV14 with increasing concentrations of CNQX. Each MEA was covered with a semipermeable lid (ALA MEA-MEM; ALA Scientific) during handling and recordings to prevent contamination from airborne pathogens.
Spontaneous electrical signals were recorded for 5 minutes using the data acquisition commercial software MC_Rack (Multi Channel Systems) as we have previously described (Kutzing et al., 2011 (link), 2012 (link); Rodriguez et al., 2018 (link)). The cultures were maintained at 37°C on a heat-controlled stage, and the signals were sampled at 20 kHz with an MEA1060-Inv-BC amplifier (Multi Channel Systems).

The spontaneous activity of hippocampal networks on MEAs was recorded using the data acquisition software MCRack (Multi Channel Systems, Germany, version 4.6.2). Recordings were performed at 37 °C on a heat-controlled stage at room atmosphere as previously described^{15 (link)–18 (link)}. Data were acquired at a sampling rate of 20 kHz using an MEA1060-Inv-BC amplifier (Multi Channel Systems, Germany). A recording solution containing the following components was used to regularize bursting behavior (in mM): 144 NaCl 10 KCl, 1 MgCl₂, 2 CaCl₂, 10 HEPES, 2 Na-pyruvate, and 10 glucose at physiological pH (pH 7.4)^{15 (link)–18 (link)}. During recording, MEAs were covered with semi-permeable lids (ALA MEA-MEM, Multi-Channel Systems) that selectively allow gases to diffuse through but that prevent airborne pathogens from contaminating the cultures. Before recording, cultures were equilibrated in the recording solution for 5-10 min. Spontaneous activity was then recorded for 5 min. Cultures were then washed once with growth medium, and treatment was applied or the conditioned medium was returned, as described below. MEA data was acquired through repeated recording of the same networks over time.

Extracellular recordings of neuronal spontaneous activity were obtained using standard 60 electrode MEA chips (60MEA200/30iR-Ti-gr), 30 µm electrode diameter spaced by a 200 µm distance, with a MEA1060-Inv-BC amplifier (Multi Channel Systems). Raw analog signals were amplified (bandwidth 1 Hz–3 kHz) and sampled at 25 kHz before being filtered with a 200 Hz high-pass filter (Butterworth second-order). Recordings were performed at 37 °C and MEAs were covered with a MEA-MEM Teflon membrane (ALA Scientific) to maintain CO₂ conditions outside the incubator. After a 3 min stabilization period, 5 min of spontaneous activity was recorded and spikes were extracted from the filtered electrophysiological signal using a threshold method with the MC_Rack software v.4.6 (Multi Channel Systems, https://www.multichannelsystems.com/software/mc-rack). Spikes that crossed a negative threshold set to 5.5 times the SD of the baseline noise were detected and stored in “mcd” files (MC_Rack). Data files generated by MC_Rack 4.6 were converted into HDF5 file format using MultiChannel DataManager (Multi Channel Systems, https://www.multichannelsystems.com/software/multi-channel-datamanager) and imported to MATLAB 9.8 (The MathWorks Inc, https://www.mathworks.com) or Python 3.7 (https://www.python.org/) through the relative toolboxes (https://github.com/multichannelsystems).