GABAA receptors are a family of chloride ion channels that predominately mediate rapid inhibitory neurotransmission throughout the CNS. The neurotransmitter GABA binds to these receptors, changing their conformation state and thereby opening the pore to allow chloride ions (Cl−) to pass down an electrochemical gradient. The flux of chloride ions hyperpolarizes the membrane leading to neuronal inhibition. However, it should be noted that, in developing animals, neurons have a higher intracellular chloride concentration at an early stage leading to an efflux of chloride and excitatory actions of GABA in immature neurons (Ben-Ari 2002).
