In the Arrenberg lab we perform two-photon calcium imaging with a Coherent Chameleon Vision S laser and a Sutter Instrument Movable Objective Microscope (MOM, Euler et al. 2009, https://sutter.com/MICROSCOPES/index.html ). As we are interested in different animal behaviors and aspects of visual processing, we make use of various experimental techniques in combination with 2P imaging to elucidate neuronal circuits and behavior.
While we use a simple custom-made LED arena to display vertical gratings around the fish to elicit eye and tail movements, and an IR (high speed)-camera to record them, we additionally employ cylindrical and spherical LED arenas – with almost 360° coverage – for more elaborate stimulations (e.g. optic flow, receptive field estimation).
We also developed fiber optic-based and DMD-based optogenetic photostimulation setups, which we can use with different transgenic animal lines to spatially activate or silence specific subsets of neurons. Together with microinjection and electroporation tools we have various additional approaches to use in tandem with calcium imaging. Additionally, we are in the process of setting up a 2nd microscope with an additional rotation axis and long wavelength multiphoton stimulation to make use of the better tissue penetration and potentially of RCaMPs (red calcium indicator) in the future.