Jump to Content

Cultured Neural Networks:

Multielectrode arrays for stimulating and recording mammalian neurons

Steve M. Potter, Tom DeMarse, Axel Blau, Daniel Wagenaar, and Jerry Pine

We wish to understand the morphological correlates of learning and memory. Systems of cultured neurons provide greatly enhanced access to cellular properties, compared to in vivo systems. The Pine Lab has pioneered the development of multielectrode substrates on which neurons are cultured for weeks or months at a time. These consist of 61 electrodes made of the transparent conductor, indium-tin oxide (ITO), on a glass substrate. We produce these using standard microfabrication processes. Because the multielectrode arrays are transparent, we can observe neuronal morphology, using an inverted microscope, through the bottom of the culture dish. The dish is connected to amplifiers and a computer that allows continuous stimulation of and recording from neurons lying on or near electrodes.

We use cultures of dissociated neurons from rat embryos, which rapidly form synapses in culture and develop complex patterns of spontaneous activity. By eavesdropping with the ITO electrodes, we can begin to decipher the electrical language that neurons speak. By electrically stimulating groups of neurons with various patterns of "simulated action potentials" we hope to observe morphological changes in the cultured neural networks that might indicate how neurons in living brains change when we learn something new. These might involve changes in synapse number or size, outgrowth or pruning of dendritic and axonal arbors, formation of dendritic spines, or perhaps interactions with glial cells.

By studying the basics of how electrical activity influences neuronal morphology, and how these changes in morphology then alter the networks' electrical properties, we will provide useful parameters for computer models of neural networks. This will allow us to develop artificial learning systems that take advantage of some of the clever adaptations that have evolved over the ages in natural neural systems.

Neuron culture on MEA

Mature superior cervical ganglion neuron culture growing on an ITO multielectrode array. Phase contrast optics are adjusted to show the transparent leads to the electodes, which form a hexagonal array in the center, with 70 um inter-electrode spacing. Leads are insulated with a layer of silicon nitride, and electrodes are plated with platinum black.

Culture dish with MEA

Neural cell culture dish with multielectrode array. The ITO conductors are not insulated near the edges of the glass, where they contact 64 preamplifiers through a conductive rubber zebra strip. The electronics is set up for recording and stimulating, from as many as 16 electrodes at a time.

Further Reading on Multielectrode arrays.

Multielectrode Array Mailing List

Back to the

August 2001 Steve Potter (steve.potter@bme.gatech.edu)