Proceedings Article | 7 March 2019
KEYWORDS: Optogenetics, In vitro testing, Neural networks, Temporal resolution, Brain, Functional magnetic resonance imaging, Animal model studies, Human subjects, Spatial resolution, Holography
In recent years, brain research has made a lot of progress with the help of new techniques such as fMRI. Most insights were gained on animal models and thus have a limited applicability to human subjects. The generation and application of human stem-cell-derived functional neural circuits therefore promises novel insights, e.g. into neurodegenerative diseases. These networks are often studied in vitro using multielectrode arrays for electrical stimulation and recording, often at low spatial resolution and specificity. Optogenetics allows for the functional control of genetically altered cells with light stimuli at high spatiotemporal resolution. Current optogenetic investigations of human neural networks are often conducted using full field illumination, potentially masking important functional information. To circumvent this, we built a holographic beam shaping setup using a fast ferroelectric spatial light modulator for single cell optogenetic stimulation, which we presented previously [1]. We achieve a lateral resolution of 8 µm in a field of view of 1.5x1.5 mm at a maximum temporal resolution of 0.6 ms using binary Fresnel holograms. In the presentation, we will first discuss our setup. Then, we will present our experiments and results on the spatiotemporal investigation of iPSC-derived human neural networks expressing wild-type channelrhodopsin-2 [2].
[1] F. Schmieder, M. Henning, L. Büttner, S. Klapper, K. Lenk, V. Busskamp, J. Czarske, “Targeted optogenetic investigation of in vitro human iPSC-derived neuronal networks”, SPIE Photonics West, 27.01.-01.02.2018, San Francisco, USA
[2] Klapper, S. D.; Sauter, E. J.; Swiersy, A.; Hyman, M. A. E.; Bamann, C.; Bamberg, E.; Busskamp, V. On-demand optogenetic activation of human stem-cell-derived neurons. Sci. Rep. 2017, 7, 14450
