Conducting polymers are class of polymer that can be synthesized directly on conductive substrates and incorporate various functional molecules into it. Its conductivity and customizability make it an ideal interface material for neuronal network research. In the first phase of this thesis, the incorporation of laminin fragments into conducting polymer films is investigated. The laminin fragments are shown to produce low impedance surfaces for neuronal recording. Furthermore, it is shown that the incorporated laminin fragments promote the adhesion of neurons to the surface. These results could provide a means for promoting a stable interface for chronic recording devices.In the second phase of this thesis, In vitro multielectrode arrays provide a framework for studying polypyrrole-mediated controlled release of neurochemicals from microelectrodes, and neuronal network dynamics in a controlled setting. We have developed a technique to achieve transient and local inhibition of synaptic transmission in cultured networks. Conducting polymer films containing the glutamate receptor antagonist CNQX are synthesized directly on the microelectrodes in the recording array. Release of CNQX is achieved through a brief electrical pulse. Through single cell patch-clamp recording, the effectiveness of CNQX release on inhibiting excitatory post-synaptic currents (EPSC) is characterized as a function of distance and time from the releasing electrode, and evidence is shown supporting a diffusion-mediated process following release. At the network level, simultaneous patch-clamp and extracellular recordings are used to characterize stimulus-evoked responses from the network. Cross correlation and a model-based variable clustering technique identify functional connectivity in a neuronal network response to electrical stimuli. Use of the controlled release of CNQX in conjunction with these techniques will allow us to examine the functional clustering of neurons in response to a given stimulation, and how a functional cluster is affected by transient, local inhibition in the network
