Impact of Carbon-Nanotube Substrate Coating in Neuronal Networks

The interest in new materials and their application in the neuroscience are growing incredibly fast. Current research interests are increasingly focusing on new artificial materials and their direct effects on the central nervous systems so that it would be possible use them to restore the original nervous function lost due to neuronal diseases or trauma. This thesis is part of the international Neuronano project and has been funded by the European Commission 6th Framework Programme. The main goal is to understand the interactions of carbon nanotubes (CNT) with the nervous tissues. Not only it focuses on how neuron stimulations and recordings instruments may be ameliorated by a CNT-neuron interface, but it also focuses on the endogenous effects of those artificial materials on neuronal activity. This thesis is divided into four themes: First, an integrated CNT-neuron system was developed to test whether electrical voltage stimulation, delivered via nanotubes, can induce neuronal signaling. It was also compared to neuronal responses evoked by voltage steps delivered via conventional patch-pipette. In the second part, the focus was on understanding the CNT-neuron interface and the tight contacts with the cell membranes that might favour electrical shortcuts between neuronal compartments. The third part is an overview of the effects of a CNT coated substrates when employed to grow long-term cell cultures. The activity was constantly monitored by an extracellular array of electrodes (MEA) for several weeks. The intimate relationship between nanotubes and cell membrane observed at single-neuron and network level, results in a more robust network activity. Finally, the MEA setup developed for cell cultures monitoring was used to investigate the effects of of BDNF on cortical cell culture model of Huntington disease.