Figure 1.

(a) GABA and glutamate-gated chloride channels share similar structures with individual subunits comprising a large extracellular N-terminal domain (for ligand binding) and four transmembrane domains (M1–M4). The mature receptor (b) is a pentamer and gates a chloride-selective channel following GABA/Glu binding. The positions of mutations implicated in cyclodiene/fipronil resistance at the GABA-R (red circles) and avermectin resistance at the GluCl (yellow circles) are shown in (a) and the corresponding regions of the mature receptors highlighted in (b). Structural models of these binding sites (AVE, avermectin and FIP, fipronil) are shown in (c) (adapted from Casida and Durkin (Casida & Durkin, 2015).