Figure 1. Dopamine is required for normal octanol avoidance response.

cat-2 codes for tyrosine hydroxylase, a key enzyme in the dopamine biosynthetic pathway [38]. cat-2 mutants are defective for octanol response, but are fully restored to wild type response latencies when tested with exogenous dopamine. eat-4 codes for a vesicular glutamate transporter that loads glutamate into synaptic vesicles [14]. eat-4 mutants respond substantially slower than cat-2 mutants, and are resistant to exogenous dopamine. Both cat-2 and eat-4 mutations are predicted nulls. In this and all the following figures, dopamine was added directly to the surface of standard NGM agar plates; distilled water was used as the vehicle control (see Materials and Methods for details). Sample sizes and detailed numbers are available in Data S1. Error bars indicate S.E.M. Comparisons are to wild type unless otherwise noted. ***p<0.0001.