GABA binds to special receptor in postsynaptic membrane. This receptor is called GABAA. GABAA consists of 5 protein subunits and forms chlorine channel. When GABA interacts with GABAA, the chlorine channel opens and chlorine ions pass through membrane into cytoplasm. Therefore membrane potential decreases from -60 mV to -90 mV causing hyperpolarization of postsynaptic membrane. This effect leads to emergence of inhibitory postsynaptic potential that makes a postsynaptic neuron less likely to generate an action potential.