Exploration (Adult zebrafish)
The aim of this experiment is to measure the amount of time needed for an adult fish to explore a novel environment, a T-shaped aquarium.
Fish are placed into the first (central) arm of the T-shaped tank, and the time needed to swim within one body length of each end is recorded. We did not record films for this experiment (because our setup was too large to fit under a camera). The data was therefore collected as a series of live observations. The tank could be scaled down to fit into the viewing field of the camera; however, a large tank may be needed to make the area difficult to explore. Test experiments with a smaller tank, or a tank that also contained large reservoirs at the end of the arms of the “T” did not provide such nice results.
The maze is a custom-made T-shaped aquarium with no large areas at end of arms. The aquarium is made from clear plastic, with white walls made by covering the outside of the setup in white paper. Each arm is 80cm long. The tank is lit from above using white light, and filled with system water at ambient room temperature (25C). All experiments were conducted in the afternoon (1pm onwards).
1) In this experiment, single fish are released into the start arm of the tank, and the time needed to swim within one body-length of the other two arms of the T is manually recorded using a timer or stopwatch.
2) Fish which stop for significant amounts of time are discarded from the experiment. A cut off of 10 minutes is defined for each fish; if the tank is not completely explored within this time the experiment is stopped and the time recorded as ten minutes.
3) The results are manually copied into Microsoft Excel for analysis. Parameters that can be compared include time needed to explore the T-maze.
4) Appropriate statistical tests can be used to analyse the data. For a comparison of two genotypes, a T-test may be sufficient. For analysis of drug treatments in different genotypes, ANOVA followed by a posthoc. test may be needed.
For a published example of this experiment, refer to Norton et al., 2011 (J. Neurosci. 31(39):13796-13807).