Insect gamma-aminobutyric acid-gated chloride channel (GABACl)

Insect gamma-aminobutyric acid-gated chloride channels (GABACls) are essential components of the insect central nervous system, where they mediate fast inhibitory neurotransmission (Sattelle et al., 1991, PMID: 1681331). These receptors belong to the Cys-loop superfamily of ligand-gated ion channels and are typically pentameric, with the Resistance to dieldrin (RDL) subunit being the most widely characterized (ffrench-Constant et al., 1991, PMID: 1848318). Upon GABA binding, the channel opens to allow chloride ion influx, causing neuronal hyperpolarization (Bloomquist, 1996, PMID: 8907073). They are major targets for various insecticide classes, including phenylpyrazoles like fipronil and the newer isoxazolines like fluralaner, which act as non-competitive antagonists (Gassel et al., 2014, PMID: 24434728). While structurally related to mammalian GABA-A receptors, insect GABACls exhibit distinct pharmacological profiles that provide high selectivity for insecticidal applications (Casida & Durkin, 2013, PMID: 23350987). Disruption of these channels leads to uncontrolled nervous system activity, paralysis, and death in target pests (Ozoe, 2013, PMID: 23573914).

Other names

RDL receptorInsect GABA receptorGABA-gated ion channelResistance to dieldrin subunitIonotropic GABA receptor

Non-competitive antagonism of the chloride channel pore or allosteric modulation of the receptor to inhibit chloride ion flow, leading to neuronal hyperexcitation (PMID: 23573914).