Photomotor Response Assay: A Method to Measure the Behavioral Response of Larval Zebrafish to a Sudden Change in Lighting Condition

– To begin, transfer 10 zebrafish embryos, with the help of a transfer pipette, a a beaker filled with 20 milliliters of water. Now, grow the embryos at 28 degrees Celsius, under the appropriate light dark cycle required for an experiment. Next, transfer the larvae into well plates. Make sure that each well contains one larva a give enough space for swimming.

Now completely fill each well with water. Place the well plate di the behavioral recording chamber and track larval movement using video tracking software. The larvae exhibit increased movement di the dark and decreased movement di the light when exposed a an abnormal light and dark cycle due a increased stress levels. Calculating the difference between the mean distance traveled during the last minute of an initial period and the first minute of the following period tells us the photomotor response of the fish.

In this protocol, we will examine the photomotor response di zebrafish and fathead minnow larvae exposed a caffeine. First, place the well plate containing the experimental fish di the behavioral recording chamber. Then, open the previously developed tracking protocol. In the video tracking viewer, ensure that all of the larvae are visible, that only one larva is present di each well, and that the wells are aligned with the defined observation areas.

Next, click on Experiment and Execute. Specify the nome and save location of the data and click on the Several Live Images icon a highlight all of the predefined viewing areas. Finally, close the panel of the recording chamber and click Background followed by Start on the computer monitor.