Carbon nanofiber electrode architectures are used to provide for long-term, neuroelectroanalytical measurements of the dynamic processes of intercellular communication between excitable cells. Individually addressed, vertically aligned carbon nanofibers are incorporated into multielement electrode arrays upon which excitable cell matrixes of both neuronal-like derived cell lines ( rat pheochromocytoma, PC-12) and primary cells ( dissociated cells from embryonic rat hippocampus) are cultured over extended periods ( days to weeks). Electrode arrays are characterized with respect to their response to easily oxidized neurotransmitters, including dopamine, norepinephrine, and 5-hydroxytyramide. Electroanalysis at discrete electrodes following long-term cell culture demonstrates that this platform remains responsive for the detection of easily oxidized species generated by the cultured cells. Preliminary data also suggests that quantal release of easily oxidized transmitters can be observed at nanofiber electrodes following direct culture and differentiation on the arrays for periods of at least 16 days.