Following a 1 h treatment with LD 50 concentrations of molinate, EPTC, or MeDETC, 200 000 L1 worms were pelleted, the supernatant was removed, and the pellet was frozen in liquid nitrogen. The frozen pellet was re-suspended in lysis buffer and sonicated to disrupt cell membranes. DA, γ-aminobutyric acid (GABA), and glutamate levels were quantified by HPLC through services provided by the Center for Molecular Neuroscience Neurochemistry Core Laboratory at Vanderbilt University. Neurotransmitter levels were determined by a specific HPLC assays utilizing an Antec Decade II electrochemical detector (DA) or 474 scanning detector (GABA, glutamate). HPLC control and data acquisition were managed by Millennium 32 software (Waters, Milford, MA, USA). DA, GABA, and glutamate were quantified using internal standards after separation by HPLC and were reported as ng/mg protein. Protein levels were quantified using the BCA assay (Thermo Scientific, Sunnyvale, CA, USA), following manufacturer's instructions.