Planar microelectrode arrays (MEAs) are widely used to record electrical activity from neural networks. However, only a small number of functional recording sites frequently show electrical activity. One contributing factor may be that neurons in vitro receive insufficient synaptic input to develop into fully functional networks. In this study, electrical stimulation was applied to neurons mimicking synaptic input. Various stimulation paradigms were examined. Stimulation amplitude and frequency were tailored to prevent cell death. Two effects of stimulation were observed when 3-week-old cultures were stimulated: (1) clusters of neural cells were observed adjacent to stimulating electrodes and (2) an increase in spontaneous neuronal activity was recorded at stimulating electrodes. Immunocytochemical analysis indicates that stimulation may cause both new neuron process growth as well as astrocyte activation. These data indicate that electrical stimulation can be used as a tool to modify neural networks at specific electrode sites and promote electrical activity.
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Acknowledgments This work was supported by the International Collaboration Program, NBS-ERC (Nano Bioelectronics and Systems Engineering Research Center)/KOSEF (Korea Science and Engineering Foundation), NIH, NS-044287 and the Nanobiotechnology Centre (NBTC), an STC program of the National Science Foundation under Agreement Number ECS-9876771. The authors also acknowledge use of the Wadsworth Center Advanced Light Microscopy & Image Analysis Core Facility for the work presented herein.
- Electrical stimulation
- Microelectrode array
- Neural network