Toxin Model of Autism
Thigmotaxis, or wall-hugging, is taken as a measurement of anxiety among zebrafish (and other animals). Increased thigmotaxis means the animals will avoid the center of the dish and hug the walls of their containers for a longer duration of time. (Kalueff et al., 2013). Recent meta-analyses find that about 40% of individuals diagnosed with ASD also have a comorbid anxiety disorder (Zaboski & Storch, 2018).
For each trial, a total of 20 zebrafish are placed in the thigmotaxis testing plate at the same time. Each trial is then recorded for a duration of 45 minutes with no acclimation period.
All recordings are then ran through ImageJ where the locations of all 20 zebrafish are measured on the plate. The XY Coordinates of all 20 fish are then used to calculate several behavior essays, including:
ImageJ - XY Coordinate Demonstration
Distance from Edge
The distance of each zebrafish from the edge of the plate (and from the center point of the plate) is calculated for each trial. The averages of these distances on all trials is then compared across toxin exposure groups.
For each trial, the distances of each zebrafish from every other zebrafish is calculated to asses the nearest neighbor for each. These distances are then averaged and compared across toxin exposure groups.