Meta-Biol

• Pathways

Gamma-aminobutyric acid (GABA) is the chief inhibitory neurotransmitter in the mammalian central nervous system. GABA exerts its effects through two ligand-gated channels and a the GPCR GABAB (Kaupmann K et al, 1998), which acts through G proteins to regulate potassium and calcium channels. GABAB can only bind GABA once it forms a heterodimer composed of the GABABR1 and GABABR2 receptors (White JH et al, 1998). The effects of this dimer are mediated by coupling to the G protein alpha i subunit, which inhibits adenylyl cyclase (Odagaki & Koyama 2001).