Engineering principles to design and analyze patterned neuronal cultures using multielectrode arrays

This dissertation addresses several issues related to the construction of reliable and reproducible patterned neuronal cultures on planar multielectrode arrays (MEAs) for biological experiments. Discussed problems include multichannel recording and stimulation for multi-dimensional data analysis, the effect of electrode geometry on spike detection, the longevity of patterned cultures on MEAs, reliable extracellular spike detection, interference with astroglial cells in terms of neuronal confinement and spike detection. MEAs were used to record evoked responses as well as spontaneous activity of patterned cultures in vitro. These cultures showed synchronized bursting activity after 2 weeks and time-locked responses in respond to electrical stimulations. Different electrode configurations were tested to study the relation between cell/electrode coupling and spike waveforms. An epoxy terminated organosilane (3-gylcidoxypropyl trimethoxysilane) was used as an easy and reproducible protein linker that can produce a stable long-lasting cell pattern for the study of patterned network in vitro. Metal electrodes of MEAs were chemically modified with organosilane or alkanethiol based self-assembled monolayers to fabricate cell-attractive electrodes. The electrode modification did not degrade the capability of neural recording, but expected cell migration toward electrodes was not observed. The growth of astroglial cells was characterized by measuring the compliance to underlying protein or neuronal patterns. Majority of astroglial cells stayed near neurons, which resulted in a confined growth of both neurons and astroglial cells. The results in this dissertation are expected to contribute to the development of in vitro model for basic neuroscience or neural prosthesis researches in the future.