Deletion mutants in gpa-14 and dop-2 habituate faster than WT, and are lowered to WT levels by exogenous dopamine. Nematode Growth Media (NGM) plates were prepared fresh the night before the assay and left overnight at room temperature. Before the assay, 10 young adult worms were transferred to the NGM plates without food. Worms were gently touched on the anterior with an eyelash hair every 10 seconds until habituated. In response to this stimulus, the worms typically move backwards. The number of times the animal moved backward until it no longer responds to the stimulus was counted. The experiment was repeated by adding 60 μl of 5 mM dopamine spread on the 90 mm plates and allowed to dry for 10 minutes. (A) Both gpa-14(pk347) and dop-2(vs105) mutants habituate faster than wild type (N2) animals. (p < 0.05, Student’s two-tailed t-test, n = 55). (B) After the application of exogenous dopamine, the habituation rates of the mutants reverted back to the wild type rates. (p = 0.37 Student’s two-tailed t-test, n = 40; error bars represent SEM values). The habituation rate of the gpa-14(pk347);dop-2(vs105) double mutant is not significantly different to either single mutant when tested in the absence (p = 0.18, Student’s two-tailed T-test) or presence of dopamine (p = 0.43, Student’s two-tailed t-test).