A new type of multielectrode array for studies of cultured neural networks is described. It is a silicon microstructure, a "neurochip': which embodies wells on the surface of a chip that are designed to contain single neurons. Each well has a platinized gold electrode which can be used for stimulating a neuron in the well or for recording from it. Each well is covered with a structure which provides tunnels through which axons and dendrites can grow out and a central hole through which the neurons can be loaded into the well. The processes thus trap the cells in the wells. The first application of this method is described: A4 x4 array of wells spaced 100 mu m apart. Results are described which show long term survival and outgrowth of neurons from the wells, and the use of well electrodes to both record and stimulate electrical activity of individual neurons.

Work in progress toward the creation of a “cultured neuron probe” is described. This is a silicon structure similar to that for a multielectrode probe, but with embedded neurons which are intended to grow out and integrate with the neurons of a host nervous system into which the probe has been inserted. Each probe neuron is in close proximity to an electrode which is designed for extracellular estimation and recording from the probe neuron. In this way the probe neurons may provide a highly specific long-term communication link between external electronics and the host. Initial experiments to establish the feasibility of the concept will be done in rat hippocampus