Gamma-aminobutyric acid-gated chloride channel (GABACl) (GABACl)

Mite and acari gamma-aminobutyric acid-gated chloride channels (GABACls) are essential inhibitory neurotransmitter receptors within the central nervous system of arachnids, including ticks and mites [1]. These receptors are members of the Cys-loop superfamily of ligand-gated ion channels and function by mediating fast inhibitory synaptic transmission; upon binding the neurotransmitter GABA, the channel opens to allow chloride ion influx, resulting in neuronal hyperpolarization [2]. In the field of veterinary and agricultural science, these channels serve as the primary target for several major classes of acaricides, such as phenylpyrazoles (e.g., fipronil) and isoxazolines (e.g., fluralaner, afoxolaner) [3]. These compounds typically act as non-competitive antagonists, binding to the inner pore of the channel to block chloride conductance, which induces lethal hyperexcitation, convulsions, and paralysis in the target parasite [4]. The high selectivity of modern acaricides for arthropod GABACls over mammalian GABA-A receptors is a cornerstone of their safety profile in domestic animals and humans [5]. Sources: [1] Bloomquist, J. R. (2003). Arch. Insect Biochem. Physiol.; [2] Buckingham, S. D., et al. (2005). Mol. Pharmacol.; [3] Gassel, M., et al. (2014). Int. J. Parasitol. Drugs Drug Resist.; [4] Zhao, X., et al. (2003). Pest Manag. Sci.; [5] Casida, J. E. (1993). Arch. Insect Biochem. Physiol.

Other names

RDL receptorResistance to dieldrin proteinIonotropic GABA receptorGABA-gated chloride channelArthropod GABA-A receptor

Non-competitive antagonism of the chloride channel pore, preventing the influx of chloride ions and leading to neuronal hyperexcitation and paralysis.