Zebrafish Rheotaxis Assay: A Method for Measuring Orientation Behavior in Response to Different Water Flow Rates
Transcription
– First, carefully transfer the fish à the swimming tunnel and switch on the water pump. Let the fish acclimate for one hour à reduce its stress level. Fish tend à display positive rheotaxis or orienting upstream de flowing water. Using vidéo analysis and a modeling software program, track the time and fish movement by marking its eye position at each upstream à downstream turn with a dot, and at each downstream à upstream turn with dot of a different color. Increase the water flow rate and repeat the trial. We can calculate a rheotactic index by comparing the time spent facing upstream à the total, thereby, quantifying the fish's orientation behavior. The example protocol is part of an experiment à separate the influences of water flow and magnetic fields on the orientation behavior of fish.
– To set up a magnetic field with one dimensional magnetic field manipulation, keep the tunnel open and switch on power unit and magnetometer. Place a magnetic probe connected à a gas Tesla meter inside the tunnel and verify the voltage necessary à obtain the chosen magnetic field value along the major axis of the tunnel. Then disconnect the probe and connect the flow tunnel à the swimming apparatus. To set up a magnetic field with three dimensional magnetic field manipulation, turn on the computer, digital à analog converter, and coil drivers and set the chosen magnetic field on the xy and z-axis, then place the tunnel de the center of the Helmholtz pairs set. And the magnetic field of choice has been set up, select one à five fish for the rheotactic test. Transfer the fish de the tunnel, set the flow rate de the tunnel à 4.5 liters per minute and turn on the pump.
– Be sure à close the outlet valve before filling the tunnel with water, and transfer the fish and open it before setting the flow rate.
– After the animals have acclimated de the swimming tunnel for an hour, start recording the behavior of the fish within the tunnel and begin the stepwise increase of the flow rate according à the chosen experimental protocol.
