Figure 1. hPSC-Derived Neurons Demonstrate Measurable Network Activity Recorded on the Maestro MEA™ System

(A) hPSC-derived neurons cultured in BrainPhys™ Neuronal Medium (Catalog #05790) were plated on the Maestro MEA™ System. (B) The neurons became electrically active over a 15-week period, with a gradual increase in MFR from 0.18 ± 0.05 Hz at Week 8 to 3.68 ± 0.47 Hz at Week 16 (n = 1; mean ± SEM, 128 electrodes). (C) Raster plots show the firing patterns of the neurons across 64 electrodes at different time points. Each black line represents a detected spike. Each blue line represents a single channel burst, a collection of at least 5 spikes, each separated by an ISI of ≤ 100 ms. Each pink box indicates a network burst, a collection of at least 10 spikes from a minimum of 25% participating electrodes across the entire well, each separated by an ISI of ≤ 100 ms. Neurons cultured in BrainPhys™ Neuronal Medium demonstrate electrical activity as shown by the increased number of spikes over time. In addition, an increase in network bursting frequency was observed, suggesting that neuronal firing gradually organized into synchronized network bursts as the neurons matured. MEA = microelectrode array; MFR = mean firing rate; ISI = inter-spike interval

Figure 2. Human iPSC-Derived Forebrain Neuron Precursor Cells Increase Neuronal Activity Over 42 Days in Culture

Human iPSC-Derived Forebrain Neuron Precursor Cells (Catalog #200-0770) were generated from the hiPSC line SCTi003-A (Catalog #200-0511). The neuron precursors were then matured on a 48-well CytoView MEA™ plate (Catalog #200-0870) with STEMdiff™ Forebrain Neuron Maturation Kit (Catalog #08605). Electrical activity from 16 electrodes was measured over time using the Maestro MEA™ System. (A - D) Detected spikes (black lines), single channel bursts (blue lines; a collection of at least 5 spikes, each separated by an ISI of no more than 100 ms), and network bursts (orange boxes; a collection of at least 50 spikes from a minimum of 35% of participating electrodes, each separated by an ISI of no more than 100 ms) were recorded for each timepoint. Neuronal activity can be detected by Day 14 and increases over time throughout the 42-day culture period. (E) Mean firing rate, (F) number of bursts, and (G) synchrony index were all shown to increase over the 42-day culture period. hiPSC = human induced pluripotent stem cell; MEA = microelectrode array; ISI = inter-spike interval

Figure 3. The Maestro MEA™ System Enables Functional Evaluation of hPSC-Derived Cardiomyocytes and Assessment of Electrophysiological Responses to Pharmacological Stimuli

(A) Ventricular cardiomyocytes were derived from four hPSC lines (H1, H9, 1C, F016) using the STEMdiff™ Ventricular Cardiomyocyte Differentiation Kit (Catalog #05010) and maintained using the STEMdiff™ Cardiomyocyte Maintenance Kit (Catalog #05020). At day 25, ventricular cardiomyocytes demonstrate a characteristic MEA electrophysiology profile, including large spike amplitude, small repolarization waveform, and stable beating frequency. (B) MEA recordings of hPSC-derived cardiomyocytes (Day 27) show characteristic electrical profiles and drug response to drug response to E4031 and Nifedipine (10 nM and 300 nM, respectively; gray lines). E4031 prolonged and Nifedipine shortened the repolarization, respectively. For guidance on how to dissociate and plate hPSC-derived cardiomyocytes for MEA Assays, view our online protocol. MEA = multi-electrode array