Utilizing Multielectrode Arrays to Measure Synaptic Physiology in 3D Coculture Spheres

Begin by coating the surface of each multielectrode array or MEA with 1 millimeter of poly-ornithine to render the surface hydrophilic and incubate at 37 degrees Celsius for a minimum of four hours. Following the incubation, remove the poly-ornithine and wash the surface of each MEA with deionized water. Then, add 1 milliliter of extracellular matrix and return to the incubator for a minimum of four hours.

When ready, remove the extracellular matrix, then apply the spheres in 1.5 milliliters of medium onto the MEA surface, ensuring that the spheres are positioned on top of the electrode array. Allow to adhere for two days. To measure the electrical activity of neural spheres, place the MEA on a temperature-controlled head stage.