Extracellular recordings from patterned neuronal networks using planar microelectrode arrays

Neuronal cell networks have been reconstructed on planar microelectrode arrays (NMAs) from dissociated hippocampal pyramidal neurons. Microcontact printing (pCP) and a photoresist-liftoff method were used to selectively localize poly-Llysine (PLL) on the surface of NWAs. Haptotaxis led to the organization of the neurons into networks localized adjacent to microelectrodes. Various grids of PLL with 2-25-pm-wide lines spaced by 50-200 pm with 15-25-pm nodes at intersection points were used to guide cell body attachment and neurite outgrowth. Bursting activity with spike attenuation was observed, and multichannel recordings detected instances of coincident firing activity. Finally, we present here an extracellular recording from a -2 pm bundle of guided neurites.