Zebrafish have laterally located eyes and therefore a large field of view. This means that for an effective stimulation of visual brain areas we need to cover a comparably large area (almost the whole surround).
We currently use two different kinds of visual stimulation setups. One of which offers a 80° x 330° (elevation x azimuth) cylindrical coverage at a high temporal and spatial resolution (approx. 1.5°) using individually controllable LEDs. The fish are mounted in the center of a water-filled glass bulb, which minimizes distortions and reflections of the visual stimuli (picture?). The second one covers a spherical area of 180° x 330° using the same LED based system (picture?).
In both setups we can simultaneously record neuronal activity with two-photon calcium imaging and fish behavior (eye and tail movements) during visual stimulation by the LEDs.
Additionally,
we are in the process of constructing an entirely new setup which
utilizes a video projector (digital micromirror array combined with
LEDs) to create an immersive 240° x 360° multi-color visual environment
for the fish and which will allow us to also simultaneously record
neuronal activity and fish behavior. This will enable us to create
naturalistic visual underwater scenes while studying the fish’s
responses.
BILDERBILDERBILDER
Left: To enable unobstructed view of the whole visual field, larval zebrafish are embedded in a small drop of agarose onto a glass triangle stage, which is mounted inside a water-filled glass bulb (not drawn to scale). The glass bulb is made by the glassblower shop of the University of Tübingen. Right: Spherical stimulus arena consisting of ~14000 LEDs, in which the glass bulb can be placed.