Knowledge Base

The DanioVision Toplight Unit

This chapter explains the setup and operation of the DanioVision Toplight DVTL-0020 for the DanioVision Observation Chamber DVOC-0050.

With the TopLight Unit you can administer a light stimulus of specific color, intensity and duration above the well plate:

• White
• Pure colors: Red, Green and Blue
• A mix of the three basic RGB colors

Note: The DanioVision Toplight Unit is an add-on to DanioVision; it does not come with a standard DanioVision system.

Install the Toplight Unit

If you ordered a TopLight Unit with a new DanioVision DVOC-0050, it is already integrated in the chamber. You can skip this section.

1. Unpack the TopLight Unit.
2. Cover the lens bracket with some protective material.
3. If that has not been done yet:
   1. Insert one of the black "stops" into the middle vertical profile, as shown in the image below.
   2. Insert one sliding nut just above the "stop". Do that at both sides of the DanioVision chamber.
4. Attach the black knobs to each sliding nut.
5. Connect the White Light side of the TopLight Unit using the predefined black-white cable inside the chamber.
6. Connect the RGB side of the TopLight Unit using the predefined, multicolor cable inside the chamber.
7. Turn the TopLight Unit in such a way that the LED color that you want to use (white vs. RGB) is facing down.
8. Slide the TopLight Unit so that the thread of the black knobs is inserted in the side brackets, as shown in the next figure.
9. Untighten both left and right black knobs to enable the unit sliding up and down.
10. Slide the TopLight Unit up, until it is at the level of the lens.
11. Make sure that the TopLight Unit is kept horizontal.
12. Tighten the black knobs.

Switch Between Lights (DVOC-0050)

Switch Between Red, Green and Blue

If you have DanioVision DVOC-0050 you can create all combinations of the three basic colors using the Trial Control Settings. You do not need to exchange cable connectors. See Trial Control Settings in the section Set Up the Toplight Unit in EthoVision XT below.

Switch Between White and Colors

If you want to switch from RGB to white light (or vice versa), turn the entire TopLight Unit in order to have the right LEDs facing down towards the well plate. The RGB LEDs and white LEDs are mounted on the opposite sides of the same plate and can be identified by the label white and rgb attached.

1. Cover the lens bracket with some protective material.
2. Untighten both left and right round black knobs as shown in the next figure.
3. Slide the TopLight Unit down a few centimeters, just below the camera.
4. Pull the unit out and turn it upside down, facing the preferred LEDs down. Important: Be careful not to twist the cable at the back. Unplug both connectors temporarily to prevent this from happening.
5. Insert the unit and slide it up again.
6. Tighten both black knobs.

Set Up the Toplight Unit in EthoVision XT

Experiment Settings

1. Start EthoVision XT and create a new experiment using a template (File > New from Template).
2. Choose Setup > Experiment Settings.
3. Under Trial Control Hardware, select Use of Trial Control Hardware, then click Settings.
4. In the Hardware Interface window, select DanioVision DVOC-0050/TPC, then click OK.
5. When needed, adjust the default light settings for the White Light Stimulus. Make sure the message shown in the bottom-left corner reads Connected. Click Refresh when necessary.
6. Click OK and proceed to the next section.

Arena Settings

1. Open the Arena Settings that you want to use. Calibrate and draw the arenas.
2. In the Arena Settings pane, click Arena - Hardware Mapping and then click the Arena - Hardware Mapping button.
3. If White Top Light / RGB Top Light is already listed in the table, skip the steps below. Otherwise, click Add Device.
4. In the row that appears, under Device Type, select either White Top Light or RGB Top Light.
5. Under A1 or Arena 1 (depending on how the arenas are named), select the corresponding device.
6. To test the device, select the cell under A1/Arena 1 and click Test.

Trial Control Settings

1. Make sure you have completed the procedures described above under Experiment Settings and Arena Settings.
2. Open the Trial Control Settings for the protocol you want to use to control the TopLight Unit.
3. Under Actions - Hardware, click the button next to White Top Light / RGB Top Light. Note: Whether White Top Light or RGB Top Light is available depends on what is selected in the Arena - Hardware Mapping window.
4. In the Hardware Action window, specify:
   • The Action Name (optional)
   • The Action to perform (Light On or Light Off)
   • For the White TopLight, the Intensity Level (%)
   • For the RGB TopLight, the three Color Intensity options to combine the three basic colors. For example, to create a strong pure red light, enter 100% for Red Color Intensity and 0% for the other two color intensities.
   • The Fade Duration (in ms to hours)
5. Click Test to ensure that the light intensity is suitable for your protocol.
6. Click OK and insert the Action box in your Trial Control protocol. Test the protocol before carrying out the real trials.