Another technology involves growing dissociated neuronal cultures on micro-electrode arrays (also called multi-electrode arrays, MEAs). Neurons are plated onto MEAs which have microelectrodes embedded in the bottom of the dish. Over the course of three weeks, these cultures form networks of neurons complete with axons, dendrites and hundreds if not thousands of synaptic connections. There are multiple advantages to using this system over other technologies. Dissociated neuronal cultures on MEAs provide a simplified model with which to work (on the order of a single cortical column rather than an intact brain). The cells grow in a monolayer making changes in morphology easy to monitor with various imaging techniques. Network activity can be manipulated with electrical stimulation sequences through the array's multiple electrodes. Because the network is small, the impact of stimulation is limited to observable areas, which is not the case in intact preparations. Finally, cultures on MEAs can survive for over a year in vitro which removes any clear time limitations inherent with other culturing techniques.1 Therefore, cultures on MEAs represent an ideal model for studying neuronal connectivity.
