Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. There are two major classes of GABA receptors the GABAA and the GABAB subtype of receptors. GABAB receptors are heterodimeric G protein-coupled receptors that mediate slow synaptic inhibition in the central nervous system. Moss and colleagues (Couve, et al., 2002) recently demonstrated that the functional coupling of GABAB R1/GABAB R2 receptors to inwardly rectifying K+ channels rapidly desensitizes. This effect is alleviated after direct phosphorylation of a single serine residue (Ser892) in the cyto-plasmic tail of GABAB R2 by cyclic AMP (cAMP)-dependent protein kinase (PKA). In addition to it
