The “GABAergic” system is the main inhibitory network in the central nervous system and as such influences almost every aspect of neuronal processing and resulting behavior. γ-aminobutiric acid (GABA), released in a typical vesicular synaptic manner from gabaergic neurons, binds to GABAA postsynaptic ligand gated ion channels. GABA also binds in and around the synapse to a G-protein coupled receptor (GPCR), GABA (B). The basic functional receptor is a heterodimer composed of two similar subunits, GABA (B) R1 and GABA (B) R2.