Thermoresponsive polymer coatings to control the direction of synaptic transmission in artificial neuronal networks

• Applicants: Dr. Werner Baumann; Privatdozent Dr. Claus Duschl
• Subject Area: Microsystems
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290023374

The analysis of artificial neuronal networks is raising great expectations with regard to the understanding of neuronal information processing and for the establishment of in vitro neuro-pharmacological test systems. In order to reproduce the highly organized architecture of neuronal tissue from dissociated neuronal cells in vitro, not only the position but also the direction of synaptic transmission between the individual cells in such networks has to be precisely controlled. However, despite strong efforts of numerous work groups worldwide this has not yet been satisfactorily managed. Aim of the present project is to investigate, whether microstructured surface coatings of thermoresponsive polymers (TRP) can be used for creating neuronal networks with defined connectivity patterns. TRP coatings undergo a phase transition from a cell-repellent into a cell-friendly state in a temperature-dependent manner, which could allow for the elegant activation or deactivation of defined pathways for neurite outgrowth. With microfabrication techniques we will develop a TRP-coated cell cultivation substrate with integrated micro heating elements that will allow us to spatially control the surface temperature in the µm-range. The possibility to dynamically and spatially control the substrate`s cell adhesive properties will form the basis for a 3-step cell assay for (1) controlling the cell position on the substrate, (2) controlling cell polarization by controlling the direction for outgrowing neurites and (3) after this, allowing neighboring polarized cells to contact each other and form functional synapses. For evaluation and optimization of the neurocompatibility of our TRP coatings and cell cultivation protocols we will investigate the initial adhesion of neuronal cells on surfaces coated with TRP and additional adhesion promoters via Single Cell Force Microscopy (SCFM) and conduct cell biological, electrophysiological as well as immunocytochemical analyses. The creation of neuronal networks of defined connectivity pattern will enable new methodological approaches to important neurobiological questions for example in the context of long-term potentiation (LTP) in basic science or pharmaceutical drug development for Alzheimer`s or Parkinson`s disease.

• DFG Programme: Research Grants
• Cooperation Partners: Professor Dr. Ulrich Egert; Dr.-Ing. Steffen Howitz; Dr. Erik Wischerhoff