Microelectrode arrays for monitoring neural activity in neural stem cells with modulation by glutamate in vitro

In this study, a 60-channel microelectrode array (MEA) was fabricated and used to monitor the neural spikes and local field potentials (LFPs) of neurons differentiated from rat neural stem cells in vitro. The neurons were grown on the MEA surface to detect neural signals. Glutamate (Glu) was used to modulate neural activity during experiments. To enhance detection performance, platinum nanoparticles were modified onto the microelectrode site surface. Glutamate stimulated neural spikes and LFPs were recorded using the MEA. The average spike amplitude was approximately 70 μV in the normal state. The spike amplitude increased by 29% from 70 μV to 90 μV with Glu modulation. The firing rate increased by 69% from 4.01 Hz to 6.8 Hz with Glu modulation. The LFP power increased from 326 μW in the normal state to 617 μW with Glu modulation in the 0–10 Hz frequency band. Data analysis shows that neural activity stimulated by Glu modulation was recorded experimentally at high temporal-spatial resolution. These results may provide a new neuron detection method, as well as further understanding of neural stem cell spike firing and associated mechanisms.