In this thesis various methods are presented towards long-term electrophysiological monitoring of in-vitro neuron cultures in µ-channel devices.
A new µ-channel device has been developed. The StarPoM device offers multiple culture chambers connected with µ-channels allowing to study communication between neuron populations. For its fabrication an advanced multi level SU-8 soft-lithography master was developed that can mold µ-channels and culture wells simultaneously. The problem of aligning features across a thick SU-8 layer has been solved by integrating a chrome mask into the substrate and then using backside exposure through the chrome mask.
A long-term monitoring of neuron electrophysiological activity has been conducted continuously during 14 days in the StarPoM device. For the analysis of the recorded dataset a new software tool-chain has been created with the goal of high processing performance. The two most advanced components - O1Plot and ISI viewer - offer high performance visualization of time series data with event or interval annotation and visualization of inter-spike interval histograms for fast discovery of correlations between spike units on a device.
The analysis of the 14 day recording revealed that signals can be recorded from day 4/5 onwards. While maximum spike amplitudes in kept rising during the 14 days and reached up to 3.16 mV, the average spike amplitudes reached their maximum of 0.1-0.3 mV within 6 to 8 days and then kept the amplitudes stable.
To better understand the biophysics of signal generation in µ-channels, the influence of µ-channel length on signal amplitude was studied. A model based on the passive cable theory was developed showing that spike amplitude rises with channel length for µ-channels < 250 µm. In longer µ-channels, further growth of spike amplitude is inhibited by cancellation of positive and negative spike phase. Also, clogging of the µ-channel entrances by cells and debris helps to enhance signal amplification.
| Identifer | oai:union.ndltd.org:TDX_UPC/oai:www.tdx.cat:10803/123671 |
| Date | 08 July 2013 |
| Creators | Riss, Michael Martin |
| Contributors | Claverol Tinturé, Enric, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial |
| Publisher | Universitat Politècnica de Catalunya |
| Source Sets | Universitat Politècnica de Catalunya |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | 171 p., application/pdf |
| Source | TDX (Tesis Doctorals en Xarxa) |
| Rights | info:eu-repo/semantics/openAccess, L'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-sa/3.0/es/ |
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