Glutamate-gated chloride channel subunit; channel properties depend on the subunit composition. Glutamate binding triggers a rapidly reversible current in heteromeric channels formed by glc-1 and glc-2, while the anti-helmintic drug ivermectin and other avermectins trigger a permanently open channel configuration. Channels containing only glc-1 are activated by ivermectin, but not by glutamate alone (in vitro). The heteromeric channel formed by glc-1 and glc-2 is also activated by ibotenate, and it is blocked by picrotoxin and flufenamic acid (PubMed:7935817). Plays a role in the regulation of locomotor behavior (PubMed:16527366). Pentamer (PubMed:21572436 and PubMed:25143115). Homooligomer, forms functional heterooligomers with glc-2 (PubMed:7935817). Glutamate binding is mediated by the extracellular domain. In contrast, the allosteric modulator ivermectin binds between subunits at the periphery of the transmembrane domain, proximal to the extracellular side. RNAi-mediated knockdown causes a decrease in the duration of forward locomotion in the absence of food, and an increase in the frequency of turns. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Glutamate-gated chloride channel (TC 1.A.9.4) subfamily.