GABAA receptors are ligand-gated ion channels (LGICs), which, along with the 7-TM GABAB receptors, are responsible for mediating the inhibitory effects of GABA. They are Cys-loop family ion channels that form a pentameric intrinsic anion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon activation, the GABAA receptor selectively conducts Cl− through its pore, resulting in hyperpolarization of the neuron. This causes an inhibitory effect on neurotransmission by diminishing the chance of a successful action potential occurring.