Zantiks MWP units delivered from January 2021 include a light stimulation stand as standard which acts as a diffusing stand and as an additional bright light source with brightness control. It is useful for optogenetic stimulation, or initiation of a startle response, and comes with an LED light source for a variety of different wavelengths including white, blue, and green (Please contact us to discuss your requirements).
There is a fairly even brightness across the light plate, and we have confirmed that the plate can stimulate zebrafish larvae and adult Drosophila. However, we recommend full validation of stimulation performance in different wells for your test animals.
If you have a first generation MWP unit (delivered prior to Jan 2021) please follow the instructions and script download for the 'light plate'. If you have the second generation MWP unit please follow the instructions and script download for the 'light plate Z2'
For assembly instructions please refer to the MWP Introduction manual
Here you will find instructions for operation of the light stand from the first generation MWP unit. If you have the second generation unit (orders shipped after March 2019) please skip to the instructions for 'Light Stand Z2' below.
We are using a third party LED driver device which allows us to control the on/off and brightness of the LEDs from the ZANTIKS script and electronics. This allows the system to be fully integrated into the Zantiks experiments.
The LED driver is permanently powered from the 3 way connector plugged in as in the previous photo (CN4). CN4 each provides permanent 12V power, a 12V power source switched by relays controlled from Zanscript, and a ground connection. CN4 has power applied by default, and when power is provided here the plate will not be lit. When power is not applied then the LED will light as controlled by the voltage out from the 4th output of CN5. High voltages (10000 mv) keep the stand unlit, and low voltages (anything below about 4000mv) will have the stand at full power.
Below is a download for the demo script opto_stim.zs
Some key points to understand about this script include:
enables output of voltage on output 4 of CN5.
sets the voltage at 10000mv, which leads to the stand being off. Lowering the voltage to below about 4000mv enables the system to be high power and the light will be at full brightness. Gradually increasing the voltage reduces the LED brightness.
ZCOMMAND("C1#0 P10 C1#1")
ZCOMMAND controls the relay and pauses. "C1#0" turns off the override so that the brightness is controlled by the voltage. "P10" delays (or Pauses) for 10ms. "C1#1" turns the override back on, so the stand is unlit. Increasing or decreasing "P" here will increase or decrease the time the light is on i.e. length of light flash.
The script produces a light sequence of pulses at increasing length, followed by a sequence of varying voltage where the LED changes from maximum brightness down to lights off.
Demonstration of the opt_stim.zs sample script for the light stand
Please note: the light stand can also be operated in the relay output CN3. Unlike CN4, which provides permanent power as a default, resulting in the plate being unlit, the default from CN3 is to provide no power, resulting in the plate being lit.
If you are using the CN3 relay, the above script will work exactly the same, except you will need to edit the ZCOMMAND in the script from "C1" to "C2" in order to control the relay when the connector is in CN3.
Here you can download the opto_stim script
Please try running it with the system plugged in to see how control can work for both length of stimulus (set by P10, P50 etc.) and for brightness (by varying the control voltage).
Light Stand Z2
Here you will find operation instructions for the second generation MWP light stand. The general principal of operation is the same as the first generation model but there are some differences in the scripting language.
Assembling the Light Stand Z2
The main components of the Z2 light stand include:
- Light stand with incorporated diffuser
- LED holder (with your choice of wavelength lights)
- Control circuit to plug directly into the MWP unit
- Foam door (with hole for light plate)
The system plugs directly into the MWP, and does not require an additional power supply.
Control of the system is from the included Zanscript programming language, and incorporates control of both the brightness of the light and the duration of the stimulus.
The brightness of the light is controlled by the voltage set on output4. This is the 7th connector on the 8-way output located at CN5 of the lower board (see picture). But this can be overridden by other controls, see below.
The LED holder is connected to the control circuitry with the push connectors. The LED holder can then be attached to the light plate and inserted into the MWP unit with the foam door to prevent any excess light entering or exiting the unit (see images below).
Script Explanation Z2
The full script can be downloaded below.
A few key points about this script include:
These two lines of code enable output of voltage and sets the voltage at 10000mv, which leads to the stand being off. Lowering the voltage to below about 4000mv enables the system to be high power and the light will be at full brightness. Gradually increasing the voltage reduces the LED brightness.
Here we have set GPO3 and GPO4 to 0 which is off. Setting both of these to off results in the light stand being controlled by the 'VOLTAGE_LEVEL' on 'VOLTAGE4' above
Turning GPO4 on by setting it to 1, sets light stand to about half power
Turning GPO3 on by setting it to 1 sets light stand to full power. If GPO4 is also set to 1, the half power is overruled and the plate remains at full power.
By turning on/off GPO3 and GPO4 in various combinations, you can control light pulses at different brightness and duration. For example, if using (GPO3,0) and (GPO4,0) so that the light is off you can use the following code:
This ZCOMMAND changes GPO3 from off to on (G3#1) which switches the stand to full brightness, waits a period of 10ms (P10), before switching GPO3 back to 0 (G3#0) which turns the light stand back off. This sequence will produce a light pulse of 10ms. By increasing or decreasing the value of P in this line of code you may increase or decrease the duration of the light pulse.
The script provides examples of the various types of light or dark pulse that can be produced by varying the GPO3, GPO4, and P values. The script will run a sequence of light pulses at increasing length, followed by a sequence of dark pulses, the stand at full lux with pulses at half lux, the stand at half lux with pulses at full lux, and finally a gradual decrease in lux by varying voltage.
Demonstration of the light_stim_demo_MWP_Z2.zs sample script for the Z2 light stand plate
Script download Z2
Here you can download the script light_stim_demo_MWP_Z2
Please try running it with the system plugged in to see how control can work for both length of stimulus (set by P10, P50 etc.), by changing the brightness with GP03 and GP04, or by varying the voltage.